{"id":120022,"date":"2026-11-10T18:07:35","date_gmt":"2026-11-10T23:07:35","guid":{"rendered":"https:\/\/bgodinspired.com\/?p=120022"},"modified":"2026-11-10T18:07:35","modified_gmt":"2026-11-10T23:07:35","slug":"acorns-and-lyme-disease","status":"publish","type":"post","link":"https:\/\/bgodinspired.com\/index.php\/bgodinspired-news\/bgodinspired-science-news\/acorns-and-lyme-disease\/","title":{"rendered":"Acorns and Lyme Disease: Why Mice, Not Deer, Set the Risk"},"content":{"rendered":"<div class='booster-block booster-read-block'>\n                <div class=\"twp-read-time\">\n                \t<i class=\"booster-icon twp-clock\"><\/i> <span>Read Time:<\/span>10 Minute, 22 Second                <\/div>\n\n            <\/div><p>Every summer somebody says it. A tick on the dog, a tick behind a child&#8217;s knee, a friend who got the rash and the long course of antibiotics, and then the same line: &#8220;It&#8217;s the deer. There are too many deer.&#8221;<\/p>\n\n<p>It sounds right. Deer are big, they are everywhere, and the tick that carries Lyme disease is even called the deer tick in many places. So when a team of ecologists spent 35 years counting everything in one patch of forest, they expected the deer to show up in the data.<\/p>\n\n<p>They did not. What showed up instead was the link between acorns and Lyme disease, running through an animal most of us never think about: a mouse.<\/p>\n\n<h2>Acorns and Lyme Disease: What 35 Years in One Forest Found<\/h2>\n\n<p>Since 1991, researchers at the Cary Institute of Ecosystem Studies have been tracking a forested property of about 800 hectares (2,000 acres) in Dutchess County, New York. They count acorns. They trap and count mice. They count deer. They drag cloths through the leaf litter to count ticks, and they test the ticks for the bacterium that causes Lyme disease. In 2026 they pulled all of it together in a paper in <em>Proceedings of the National Academy of Sciences<\/em>, led by Richard Ostfeld.<\/p>\n\n<p>Three things stand out.<\/p>\n\n<ul>\n<li><strong>Deer did not predict the ticks.<\/strong> Across the full data set there was no statistically significant link between how many deer were around and how many nymphal ticks, the small stage that bites most people, turned up the next year. A weak link appeared in short slices of the data and vanished when the whole record was used. In Ostfeld&#8217;s words, &#8220;the whole data set in its entirety shows no such thing.&#8221;<\/li>\n<li><strong>Mice did.<\/strong> A year with a large population of white-footed mice was followed by about 40 percent more nymphal ticks the next year.<\/li>\n<li><strong>Acorns predicted the mice.<\/strong> Oaks do not drop the same crop every year. Some autumns they produce a flood, called a mast year. A heavy acorn crop feeds mice through the winter, mouse numbers jump the following summer, and the ticks rise the summer after that. A big acorn autumn points to a bad tick year two years out.<\/li>\n<\/ul>\n\n<p>That is the whole chain. Acorns feed mice. Mice feed tick larvae. The larvae that feed on mice are far more likely to survive to become nymphs, and mice pass the Lyme bacterium to them very efficiently. Two summers later, those nymphs are waiting in the grass at ankle height.<\/p>\n\n<div class=\"convertkit-form wp-block-convertkit-form\" style=\"\"><script async data-uid=\"6491fb8269\" src=\"https:\/\/bgodinspired.kit.com\/6491fb8269\/index.js\" data-jetpack-boost=\"ignore\" data-no-defer=\"1\" data-no-optimize=\"1\" nowprocket><\/script><\/div>\n\n\n<h2>So Are the Deer Off the Hook?<\/h2>\n\n<p>Not quite, and this is where the honest version is more useful than the headline.<\/p>\n\n<p>Adult female ticks still need a large animal for a blood meal before they lay eggs, and in most of the eastern United States that animal is a deer. Deer cannot pass the Lyme bacterium to ticks, but they keep the tick population going. Maria Diuk-Wasser, a disease ecologist at Columbia University who was not part of the study, made the distinction plainly: earlier research found that cutting deer down to very low numbers does limit ticks. But in a forest where deer are already plentiful, a few more or a few fewer does not move the needle. The deer are the floor, not the dial.<\/p>\n\n<p>So the thing everyone blamed is necessary, but it is not what changes from year to year. The thing that changes is the mouse, and behind the mouse, the acorn.<\/p>\n\n<h2>The Finding That Kept the Lead Author Up at Night<\/h2>\n\n<p>Here is the part the press summaries skip, and it is the most interesting thing in the paper.<\/p>\n\n<p>Early in the study, more mice also meant a higher share of ticks carrying the bacterium. That made sense. Mice are excellent at infecting the ticks that bite them. Then, as the years piled up, the link disappeared. More mice still meant more ticks, but not a higher percentage of infected ones.<\/p>\n\n<p>The team&#8217;s best explanation is that when mice are abundant, other animals tend to be abundant too: skunks, squirrels, opossums. Those animals feed ticks as well, but they are poor at passing the bacterium on. So they dilute the infection rate, even as the raw number of ticks goes up.<\/p>\n\n<p>Ostfeld said the collapse of that early finding &#8220;kept me up at night,&#8221; because it meant his understanding of the system &#8220;was incomplete or wrong.&#8221; Thirty-five years into a project, that is an unusual thing for a lead scientist to put in print. It is also why the study is worth trusting. Shannon LaDeau, who co-leads the program, noted that studies of this depth and length are incredibly rare, and the rarity is exactly what let the team catch their own mistake.<\/p>\n\n<p>One more surprise sits in the weather data. Lab work had suggested extreme heat and cold kill these ticks. In the forest, they simply move deeper into the soil and leaf litter and wait. A harsh winter does less to them than people hope. And warmer years, which are good for mice, were actually followed by fewer nymphs than usual. The two effects pull in opposite directions, and the authors say they still cannot tell you the net result.<\/p>\n\n<h2>What to Actually Watch, and What to Do<\/h2>\n\n<p>The study is one site in one part of New York, and the authors are careful to say the chain may run differently elsewhere. Lyme disease exists across Europe and parts of Asia too, carried by related ticks and a different mix of small hosts, so the acorn signal is strongest where oaks and white-footed mice share the woods. Still, the practical lessons travel well, and none of them cost money.<\/p>\n\n<ol>\n<li><strong>Look down in autumn.<\/strong> If the ground under the oaks is crunching with acorns this year, treat the summer after next as a heavier tick season and plan for it.<\/li>\n<li><strong>Notice the mice.<\/strong> A winter with more mice in the shed, the garage or the house is the one-year warning the researchers describe.<\/li>\n<li><strong>Stay on the path.<\/strong> Nymphs wait on low plants and in leaf litter, not on open trails. Keep leaf piles away from places children play.<\/li>\n<li><strong>Check skin after being outdoors.<\/strong> Behind the knees, the waistband, the armpits, the hairline. The nymph is the size of a poppy seed, so look slowly.<\/li>\n<li><strong>Remove a tick with fine tweezers,<\/strong> gripping close to the skin and pulling straight up. Note the date. If a spreading rash or a fever follows in the next few weeks, see a doctor and mention the bite.<\/li>\n<li><strong>Do not count on a cold winter to fix it.<\/strong> The ticks are under the leaves, waiting.<\/li>\n<\/ol>\n\n<p>We have written before about the few insects that bite and the many that do not, in <a href=\"https:\/\/bgodinspired.com\/index.php\/bible-resources\/bible-answers\/why-did-god-make-mosquitoes\/\">Why Did God Make Mosquitoes?<\/a>, and about the hidden work insects do that we only notice when they vanish, in <a href=\"https:\/\/bgodinspired.com\/index.php\/nature-and-creation\/where-have-all-the-wasps-gone\/\">Where Have All the Wasps Gone?<\/a>. This story belongs on the same shelf.<\/p>\n\n<h2>The Small Thing Was Running It All Along<\/h2>\n\n<p>Step back from the ticks for a moment and look at the shape of the story. For decades, the explanation everyone reached for was the biggest animal in the woods. The real driver was a creature that weighs less than a slice of bread, fed by a seed that falls on your head and that you kick aside on a walk. The forest was being run from the bottom, and nobody noticed because nobody was looking down.<\/p>\n\n<p>It is an old lesson, and one of the oldest collections of wisdom sayings in the world already had it. There is a passage that lists four creatures that are &#8220;little upon the earth&#8221; and calls them &#8220;exceeding wise.&#8221; The ant comes first: no strength to speak of, yet it stores up its food in summer. Whoever wrote that had spent time on the ground, watching the small things, and had decided that God had put real wisdom in them, the kind you miss if you only ever look at what is large.<\/p>\n\n<p>Thirty-five years of data in a New York forest landed on the same conclusion. The mouse and the acorn were the wise ones.<\/p>\n\n<h2>What This Changes for Your Next Walk<\/h2>\n\n<p>You do not need to fear the woods. Most ticks never find a person, and most tick bites never lead to Lyme disease. What this research gives you is a better guess about which years to be careful, and a reason to stop blaming the wrong animal.<\/p>\n\n<p>So this autumn, when the acorns are loud underfoot, make a note. Two summers from now, tuck your trousers in and check behind your knees. And the next time someone says it&#8217;s the deer, you can tell them about the mouse.<\/p>\n\n<h2>Discussion Question<\/h2>\n\n<p>The researchers spent 35 years on one patch of forest and still had to admit their early theory was wrong. Do you think long, slow studies like this are worth the cost when faster research could cover more ground, or is this kind of patience the only way to get an answer you can trust? Tell us what you think in the comments.<\/p>\n\n<div class=\"convertkit-form wp-block-convertkit-form\" style=\"\"><script async data-uid=\"6491fb8269\" src=\"https:\/\/bgodinspired.kit.com\/6491fb8269\/index.js\" data-jetpack-boost=\"ignore\" data-no-defer=\"1\" data-no-optimize=\"1\" nowprocket><\/script><\/div>\n\n\n<h2>Share This<\/h2>\n\n<ul>\n<li>A 35-year study just found deer do not predict Lyme disease ticks at all. Mice do, and acorns predict the mice two years ahead. I have been blaming the wrong animal my whole life. https:\/\/bgodinspired.com\/index.php\/bgodinspired-news\/bgodinspired-science-news\/acorns-and-lyme-disease\/<\/li>\n<li>Heavy acorn autumn means a bad tick summer two years later. The chain is acorns, mice, ticks, and the deer were never the dial. Worth a read if you walk in the woods: https:\/\/bgodinspired.com\/index.php\/bgodinspired-news\/bgodinspired-science-news\/acorns-and-lyme-disease\/<\/li>\n<li>The lead scientist on a 35-year Lyme study said one finding &#8220;kept me up at night&#8221; because it proved his own theory wrong. That is the kind of science I trust.<\/li>\n<\/ul>\n\n<h2>Questions People Ask About Acorns and Lyme Disease<\/h2>\n\n<h3>How are acorns connected to Lyme disease?<\/h3>\n<p>Acorns are connected to Lyme disease through mice. In a heavy acorn year, white-footed mice have more food through winter and their numbers rise the following summer. Tick larvae that feed on mice are more likely to survive to the nymph stage and to pick up the Lyme bacterium. A 35-year study at the Cary Institute in New York found a heavy acorn crop predicted a rise in nymphal ticks two years later.<\/p>\n\n<h3>Do deer cause Lyme disease?<\/h3>\n<p>Deer do not spread the Lyme bacterium to ticks, and the 35-year Cary Institute study found no statistically significant link between deer numbers and the number of nymphal ticks in a forest where deer were plentiful. Deer still matter, because adult female ticks need a blood meal from a large animal before laying eggs, and earlier research found cutting deer to very low levels can limit ticks. In most places, though, year-to-year tick risk tracks mice and acorns rather than deer.<\/p>\n\n<h3>Why are mice so important for Lyme disease?<\/h3>\n<p>White-footed mice are important for Lyme disease because they feed large numbers of tick larvae and pass the Lyme bacterium to them very efficiently. The 35-year Cary Institute study found a year with many mice was followed by about 40 percent more nymphal ticks the next year. Other small hosts such as skunks, squirrels and opossums also feed ticks but transmit the bacterium poorly, which can lower the share of infected ticks.<\/p>\n\n<h3>Can you predict a bad tick year?<\/h3>\n<p>The Cary Institute researchers say a heavy acorn crop gives about a two-year warning of a bad year for nymphal ticks, and a large mouse population gives about a one-year warning. These signals were measured at one forest site in Dutchess County, New York, so the exact timing may differ in other regions, but acorn and mouse counts are being proposed as forecasting tools for public health planning.<\/p>\n\n<h3>Does a cold winter kill Lyme disease ticks?<\/h3>\n<p>A cold winter does less than most people expect. Laboratory studies suggested extreme cold and heat kill blacklegged ticks, but the long-term field data from the Cary Institute showed ticks survive by moving deeper into soil and leaf litter. The study also found warmer years were followed by fewer nymphal ticks than usual, so the overall effect of weather on tick numbers is still unclear.<\/p>        <div class=\"booster-block booster-reactions-block\">\n            <div class=\"twp-reactions-icons\">\n                \n                <div class=\"twp-reacts-wrap\">\n                    <a react-data=\"be-react-1\" post-id=\"120022\" class=\"be-face-icons un-reacted\" href=\"javascript:void(0)\">\n                        <img decoding=\"async\" src=\"https:\/\/bgodinspired.com\/wp-content\/plugins\/booster-extension\/\/assets\/icon\/happy.svg\" alt=\"Happy\" title=\"\">\n                    <\/a>\n                    <div class=\"twp-reaction-title\">\n                        Happy                    <\/div>\n                    <div class=\"twp-count-percent\">\n                                                    <span style=\"display: none;\" class=\"twp-react-count\">0<\/span>\n                        \n                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A heavy acorn autumn means more ticks two summers later. What to watch.<\/p>\n","protected":false},"author":1,"featured_media":120021,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_wp_convertkit_post_meta":{"form":"-1","landing_page":"0","tag":"0","restrict_content":"0"},"footnotes":""},"categories":[5226,3711,3708],"tags":[],"class_list":["post-120022","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bgodinspired-science-news","category-health-and-wellness","category-nature-and-creation"],"_links":{"self":[{"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/posts\/120022","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/comments?post=120022"}],"version-history":[{"count":1,"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/posts\/120022\/revisions"}],"predecessor-version":[{"id":120023,"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/posts\/120022\/revisions\/120023"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/media\/120021"}],"wp:attachment":[{"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/media?parent=120022"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/categories?post=120022"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/tags?post=120022"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}