This Mite-y Beetle Buries the Dead to Start a Family
Insects called burying beetles haul mouse carcasses down into the dirt and prep them to feed their future offspring. Also known as carrion beetles, they have some stiff competition … and some help from tiny traveling mites.
TRANSCRIPT
Why is this dead mouse moving?!
Well, death is a magnet for life. And there’s something down there. It’s a yellow-bellied burying beetle, hustling to hide this mouse, before, say, a raccoon gets it.
It also has to work faster than these ants, which are here for bits of mouse to feed their larvae.
And there’s this fly, too, looking for a place to lay her eggs. More on that later.
The beetle, also known as a carrion beetle, doesn’t do the killing. It just profits off creatures whose time has run out, here on the California coast.
Just as small carcasses begin to get fragrant, the beetle sniffs them out with its sensitive clubbed antennae.
Over the next few hours, it digs up dirt from below the mouse. It pushes and pulls.
Yes, that is just one beetle doing the hauling, moving that carcass safely underground.
This carcass is about to become a nursery and a buffet.
Now it’s time to get something else done. The beetle hooks up with a partner. Underground, they roll the carcass into a ball. This reduces the amount of flesh exposed to bacteria … and decay. That’s one way to bond on a date!
The mouse takes on the color of dirt. The beetles dab the ball with microbes, from their butts, that work like a preservative, slowing down the rotting. The meal has to keep so they can feed their offspring. See that?
A few days later, larvae hatch from the eggs mom laid right next to the carcass. They’re hungry and mom feeds them bits of prechewed mouse into their mouths. When they’re big enough, the larvae crawl right into that “pantry” and help themselves. It’s a party in here!
Meanwhile, some other creatures are also flourishing on this mouse carcass: mites that rode in on the beetles. They’re called “phoretic,” which means they’re piggybackers. They reproduce like mad and look like a huge nuisance to their carriers.
“What? Do I have something on my face?”
But the mites actually help the beetles.
Remember the fly that laid her eggs on the carcass? Well, the mites devour fly eggs, which would otherwise grow into maggots hungry for this delicacy.
The mites also eat a few beetle eggs from time to time. It’s the price the beetles pay so their larvae have the mouse to themselves.
But if a beetle family is large, a carcass sometimes isn’t enough to feed all the hungry mouths. So, mom gets rid of a few of her larvae … by eating them.
She eats some so that others can thrive … continuing that strange dance between life and death.
Hi, it’s Laura. If you love learning about animals and nature, subscribe to our free Deep Look weekly newsletter, called “Nature Unseen.” Link in the description. You know what other animals perform great feats to survive? Red fire ants. During hurricane season, when floodwater flows into their nest, they build a raft with their own bodies. And they use their larvae as giant floaties. Stay dry!