Sometimes, to get where you want in life,
you need to go all out. Fleas need to get off the ground and on to
someone they can exploit. That’s bad news if you’ve got fur or feathers.
There are more than 2000 flea species. Each partial to its own kind of creature.
But the one you’ll most likely cross paths with is the cat flea.
Fleas are one of nature’s greatest jumpers… taking a gigantic leap almost too fast to
comprehend. They’re small and narrow — like a little
sesame seed with legs. Their fly ancestors lost their wings millions of years ago to help them slip through fur with ease. Fleas are tough to get rid of. Stiff backwards-facing hairs catch on fur
when you try to pick them out. Try to squish one? Nope! Their flexible bodies are armored with rugged
plates called sclerites. Adult fleas only eat one thing– blood. This cat flea prefers cat blood. But in a pinch, it’ll latch on to you too. They lay eggs that drop from the cat’s body into its bedding. A few days later, they hatch, and worm-like larvae wiggle out. The hungry larvae scavenge for food. Their favorite meal comes from mom and dad. Adult flea poop — that’s just semi-digested blood. Now, who could turn that down? The larva curls up into a cocoon it makes from whatever dirt, sand or other materials it finds nearby. A few days later… voila! All grown up. Now this hungry flea needs a warm body to call home.
Its jump is super fast: 100 times faster than the blink of an eye.
But it takes more than muscle to move that fast. The flea can compress itself like a spring, thanks to a rubbery protein called resilin in its legs and body. First the flea pulls in its over-sized rear legs and locks them in place.
It squeezes and flattens its body, squishing the resilin and building up energy for the
jump… then… it releases the energy all at once. The flea tumbles through the air, legs extended. With a lot of effort, and a little luck, it’ll
land on its target and the whole incredibly itchy cycle will begin again. Hi Deep Peeps. Lauren here.
You may have noticed a different – but familiar – voice on our episode today.
My good friend and fellow science reporter Laura Klivans is back to take over for me
as the new official Deep Look host.
Here’s a playlist of our 10 Deep Look episodes she’s already hosted. Thanks, Lauren! I’m thrilled to be back.
If you miss Lauren’s voice – you can follow her now over at NPR where she’s the new climate reporter. Link is in the description. Thanks.