What is so scary about a cockroach anyway? Yes, they’re creepy looking pests, but more specifically, they are the most primitive winged insects still with us. They are modern day ancestors for bloody sake! They prefer warm conditions, which is why they can be found within buildings, but can survive better than cavemen in freezing temps. They’re mainly nocturnal (except for the Asian cockroach, which seems to prefer [reading] light[s in hostels]). The spines on their legs help in locomotion on difficult terrain (actually their legs have inspired robotic legs). They leave behind chemical trails in their feces, as well as emit airborne pheromones for swarming and mating (nothing a Lysol wipe can't fix). Female cockroaches may produce up to 300 to 400 offspring in a lifetime and development from eggs to adults takes apps 3-4 months. Males have been known to live for up to four years. They are often heard hissing or chirping (these sounds have regional additions and variations for mating purposes).
Cockroaches are omnivorous (except for a few wood-eating species) and breath through the tracheae. They can remain capably active for over a month without food, but still need only very limited resources (eg. glue form postage stamps) and can go without air for over 45 minutes. Drowning them would be ineffective. They can survive even after being decapitated. They are radiant resistant…it is popularly suggested that cockroaches would inherit the earth if humanity destroys itself in a nuclear war. Cockroaches are linked to allergic reactions in humans, but nothing more dangerous than that. In fact, ethnic tribes in Southern China near the Vietnam border use cockroaches to treat ailments and energies (such as burns, heart disease, hepatitis, trauma, etc). Hm, maybe I’ll get myself some cockroach balm while I’m here. Even more, in the 1870s, many New Orleans folk had strong faith in a remedy of boiled cockroach tea (and kids, you can even try that at home).
Point is, cockroaches are bloody cool. I'd guess, if a transformer were a bug, it’d probably be a cockroach.