Why Are These Wasps Stockpiling Ant Corpses in Their Nests?

A group of researchers made a macabre discovery when they discovered a new species of wasp in China's Gutianshan National Nature Reserve. These wasps lay their eggs in nests that are stuffed with the corpses of freshly-killed ants. As if wasps weren't creepy enough.

The new species is a type of spider wasp, described this week in PLoS One. The researchers found that when the wasps stuffed their eggs inside the wooden tubes where they were nesting, they capped off the tubes with a pile of ant corpses. Above, you can see one of their tube nests, with the eggs in separate chambers — and one chamber reserved for ant corpse business.

Though some wasps are known to leave maimed insects behind for their newly-born babies to eat, that's not likely the case here.

Over at Slate, the researchers told reporter Jane Hu their theories about why the wasps are doing this as camouflage:

[Michael] Staab and his colleagues think the bodies may help protect wasps' nests through their scent. Ants communicate mostly by pheromones, and even after ants die, that scent lingers for days. Mother wasps abandon their larvae after nest-building, so the young are very vulnerable: Other animals co-opt wasps' nests for their own eggs or break in to eat the larvae inside. Ants' smell could deter animals from approaching the nest, especially if those animals have had bad experiences with ants in the past. They could also serve as an olfactory camouflage.

Basically, these wasps seem to be masking the scent of their babies with the smell of ants. Sort of like hiding your human baby in a pile of zombie corpses. As you do.