There are many ways of course that cockroaches are different than humans, but mostly lets discuss bodies. For instance why do cockroaches die on their backs with their legs in the air? To know the answer to this question is simply to look at them. Cockroaches have rounded backs that are greasy, with a body that is able to be flat. That flat body is what allows them to squeeze in through the cracks in your walls. Commonly used insecticides induce muscle spasms and can confuse the cockroaches, which of course makes them look like a turtle stuck on their back. Their body oddities are also what allows them to walk up walls whereas of course we humans cannot. Cockroaches have three sets of legs which allow them the ability to go places and do things we can't like walking up a wall or across glass without slipping.  Each set of these legs is controlled by their own nerves with a foot like claw at the bottom of the leg. There is no central nervous system like and brain in a human. Cockroaches can live without its head because there literally is no brain in there. If left in the wild, cockroaches typically will stick in groups of up to 50 to try to secure safety. For more information on cockroaches, please click here