Daddy longlegs are the spiders we run across the most often, right? Think again.
How many body parts does a spider have? Two. A “head” (called a cephalothorax) and an abdomen (where that sticky silk comes from). How many body parts does a daddy longlegs have? One. So, these animals aren’t even spiders. Daddy longlegs are one of many animals called opilionids (oo-pill-ee-OH-nidz). They are in the same animal class as spiders (Arachnida), and they all have long legs so they look like spiders—but they’re a separate order.
Opilionids aren’t dangerous to humans, but their predators had better watch out. Scientist Dr. Thomas Eisner discovered that a daddy longlegs carries toxin in its armpits. His research began one day when travelling through Texas. He picked up a daddy longlegs and smelled it— that’s right, his nose was his scientific instrument. He observed an odd smell so he carted the creature back to his motel room and studied it. The smell was a toxic chemical called benzoquinone (say BEN-zo-qwi-NO-ne). So of course, Dr. Eisner wanted to know more about that!
The chemical is toxic when it is a gas or a liquid, but not when it is a solid. On the side of the animal’s body–basically in its armpit–Dr. Eisner found a sac-like gland. In that gland? Solid benzoquinone.
When a predator such as an ant threatens the daddy longlegs, he spits up a drop of gut juice. That liquid travels down a groove from his mouth to the gland. In less than a second, he dissolves a bit of that benzoquinone into the liquid and creates toxic ammunition. You know those two long legs daddy longlegs use as feelers? He dips the tip of one of them into the toxic drop then slaps it on his predator.
Take that you scary ant! They flee.
The opilionid can reload his feelers up to thirty times from one toxic drop. When his ammo runs low, all he needs to do is drink water and spit again. Other types of opilionids skip the feelers and just let the liquid ooze out around their body, creating a super toxic safety shield.
What other secrets might opilionids be hiding? Not many people study them, so who knows?!? Maybe you will sniff out a discovery!
Some bugs litter. Some pass gas. Some bugs throw their poop! Discover ten of the rudest, crudest bugs around. Full of scientific facts, humor and just the right amount of yuck, Heather L. Montgomery's How Rude! features a countdown of the top 10 bad bugs who just won't mind their manners. One part illustration and one part photography, How Rude! is hilarious, informative, and seriously gross!
MLA 8 Citation
Montgomery, Heather L. "Toxic Armpits." Nonfiction Minute, iNK Think Tank, 6 Dec. 2017, www.nonfictionminute.org/ Toxic-Armpits.
Polar bears are built to withstand some of the coldest temperatures on the planet. Their brown and black bear cousins avoid the winter cold by digging dens and sleeping. But, except for pregnant females, polar bears spend the arctic winter outside where temperatures could be -40° F (which equals-40 °C) and windy. That’s too cold for humans. You could go outside, but only for only a few minutes with every part of your body completely covered. And if you didn’t wear goggles, your eyelashes would freeze and break off if you touched them.
Polar bears are warm-blooded like us with a body temperature of about 98°F/37°C. But they are invisible to night-vision goggles that pick up the infrared rays that warm-blooded creatures, including humans, give off. Why? Nature has given polar bears enough insulation to prevent body heat from escaping. They are toasty warm and comfortable in the frigid arctic.
Their heat insulation is in several layers. Under their skin, there is a 4-inch (21.5 cm) layer of fat. Next to the skin is a dense layer of woolly fur that also keeps heat in. The fur you see is a thick layer of long, colorless guard hairs that shed water quickly after a swim. They are stiff and transparent and hollow. In the arctic sunlight, the hairs act like mirrors and reflect white light, which acts as camouflage against the snow so the bears are not seen by their prey. Polar bear skin is actually black, so that it can absorb the invisible warm infrared rays of the sun and the bear’s own body heat, both of which are reflected back by the guard hairs.
Most warm-blooded animals raise their body temperatures through exercise. Polar bears hunt seals, which they don’t often chase. They prefer to sit at the edge of an ice floe and wait for dinner to arrive. At best, they’ll lumber after a seal at four and a half miles (7.25 km) an hour, raising their body heat to 100°F (38°C). When that happens, they go for a swim to cool off.
Cold won’t kill off the polar bears, but global warming can. As polar ice disappears, so does the hunting ground for seals. Not so cool!
Close up, the polar bear guard hairs are transparent. This allows the infra-red light (heat) from the sun to pass through them to be absorbed by the black skin under the hairs. The hairs also act like mirrors , reflecting back to the skin any infra-red radiation escaping from the bears body so it can be reabsorbed. Thus, the insulation is just about perfect with no infra-red radiation escaping. The hairs are also coated with oil so they drain quickly after a swim.
Vicki Cobb's This Place Is Cold shows how the latitude of Alaska affects the lives of the plants, animals and people who live there. It is gloriously illustrated by Barbara Lavallee, a long-time Alaskan resident and artist.
Vicki is a member of Authors on Call—she can visit your classroom with interactive videoconferencing: Read more about her here.
MLA 8 Citation
Cobb, Vicki. "The Way Polar Bears Keep Warm Is Cool." Nonfiction Minute, iNK Think Tank, 29 Nov. 2017, www.nonfictionminute.org/The-Way-Polar-Bears-Keep-Warm-Is-Cool.
Earth’s temperatures are getting warmer. In fact, sixteen of the seventeen hottest years on record have occurred since the year 2000. These warmer temperatures are driving larger, long-term changes in our planet’s weather and climate. Scientists refer to these changes as “climate change.”
In a few places, climate change might be welcome, but around the world, warmer temperatures and other changes are leading to a host of problems from rising sea levels to more extreme weather events and the spread of harmful human diseases.
Professor Scott Mills, from the University of Montana, wanted to see how climate change might be affecting one particular animal called the snowshoe hare.
Snowshoe hares live in regions of North America that receive snow every winter. The hares, in fact, change their coat color from brown to white and back again every year. This helps camouflage them against their background—and hides them from the eyes of lynx, owls, and other hungry predators.
Here’s the thing: snowshoe hares can’t choose when they molt, or change their coat color. Molt timing is controlled by their genes, which are part of the DNA inside their bodies. If a hare’s genes make it molt to white in October, but snow doesn’t fall until December, the hare will stick out like a light bulb against the brown earth. And that’s a problem. Why? Because almost everywhere on earth, the length of time with snow on the ground is growing shorter and shorter.
To find out if shorter winters might harm hare populations, Scott and his team spent three years tagging and following hares. They measured how many were born, how many died, and what they died from. They also recorded whether the hares were matched or mismatched against their backgrounds.
They discovered that predators killed mismatched hares significantly more often than hares whose coats match their backgrounds. Scott and his team also calculated that over the next one hundred years, this greater mortality, or death rate, could lead to the decline or disappearance of many snowshoe hare populations.
The good news? Different hares molt at different times. This may help some hare populations adapt to shorter winters and longer periods without snow.
Hares are not the only animals affected by shorter winters. More than twenty species of animals including lemmings, weasels, hamsters, and Arctic foxes change their coat colors every year. Scott’s research helps us predict what might happen to these animals—and decide what we can do to protect them.
Scott’s discoveries about Montana snowshoe hares, together with experts’ predictions about our future climate, indicate that hares will be mismatched between 5-½ and 10 weeks by the end of this century.
Before tagging and putting a radio collar on a snowshoe hare, Professor Mills and his team must weigh and measure it.
This snowshoe hare has been tagged and fitted with a radio collar—and is now ready to help scientists learn more about snowshoe hare survival.
Even from a great distance, a mismatched hare stands out like a glowing light bulb. (Photo Courtesy of L. Scott Mills research laboratory)
Besides serving as popular prey for predators, snowshoe hares are irresistibly cute. This is a young hare, also called a leveret.
Sneed B. Collard III is the author of more than eighty award-winning books, many focusing on science and the natural world. His entertaining memoir Snakes, Alligators, and Broken Hearts—Journeys of a Biologist’s Son recounts his challenges and adventures growing up as the son of divorced biologist parents, and the experiences that would one day lay the foundation for his writing career. He is a dynamic speaker and offers school and conference programs that combine science, nature, and literacy. To learn more about him and his talks, visit his website, www.sneedbcollardiii.com.
This book was reviewed by Vicki Cobb in the Huffington Post: "The Cheeseburger of the Forest".
MLA 8 Citation
Collard, Sneed B., III. "Hopping Ahead of Climate Change." Nonfiction Minute, iNK Think Tank, 15 Nov. 2017, www.nonfictionminute.org/hopping-ahead-of-climate-change.