Scientists have created an "atlas of vertebrate decay," which documents — with pictures! — the changes a handful of species go through as they decompose. And yes, there is an actual scientific purpose behind this gruesome pursuit.
Humans are one of 60,000 species that share a 500 million year old common ancestor. This creature was the ancestor of almost every vertebrate species, but it had a sixth sense that most of its descendants long since lost.
In the normal course of things, beetles will generally stick to eating insects, worms, and any dead meat it happens to come across. But if conditions are right, one species will kill and devour frogs many times its own size.