Why do roaches die on their backs?

I keep finding dead roaches flipped upside down around my house. Is that normal? Do cockroaches play dead? 

No, cockroaches don’t play dead; what you’re seeing are dead roaches. Cockroaches die on their backs because when they die, their muscles relax and their legs give out. Because cockroaches have a rounded, top-heavy exoskeleton, they tip over, and on smooth floors they can't right themselves. That's why you almost always find them belly-up.

So is it a good sign that they’re dead? If you've recently had a treatment, finding cockroaches upside down like this could be a good sign, as the treatment is working. However, without treatment, it could mean that there is a bigger infestation hiding in your property and it’s time to call in the cockroach exterminators.