insects

Up until recently, habituation -- a simple form of learning -- was deemed the exclusive domain of complex organisms with brains and nervous systems, such as worms, insects, birds, and mammals.

Ecdysozoans include all the arthropods, including insects, crustaceans, and spiders, as well as tardigrades, and roundworms, or nematodes.

The scientists had also studied insects found on the bodies to establish the date of their deaths.

That includes the millions of species of insects, arachnids, and nematode worms that make up a major animal group called the Ecdysozoa.

He still wonders whether there was anything he could have done to save the insects.