Why do insects (flies) put their legs together when they die (as if they're praying)? Other animals don't seem to have an organized pose to die in. Or do they?

A good working theory is that this is caused by Rigor Mortis and the anatomy of insect legs.

In most cases, the muscles that pull the leg down (or closer together) are larger than the ones that pull the leg up. This is because those muscles (flexors) must support the insect's weight:

(Click for larger view)
![Insect leg anatomy and forces]( "Click for larger image.")

When the muscles contract after death, the larger muscles win out, causing the legs to move together.

From _Why Do Insects Cross Their Legs When They Die?_:

> I suspect this is rigor mortis -- that post-death stiffening that occurs due to a chemical transformation of muscle tissue -- contracting legs as much as possible in the directions of least resistance, says **Brian Farrell, an entomologist at Harvard University**.