When no other food sources are available, due to shortages or sudden growth in a cockroach population, cockroaches may turn to attempting to feed on living human beings, according to Orkin. Cockroaches will readily consume dead humans and all other forms of carrion, but they will not try to feed on live prey unless an infestation becomes truly massive and is left totally unchecked, at which point it will be forced to seek out new sources of food.
There have been many recorded cases of cockroaches on ships at sea turning to humans for sustenance, according to Orkin. No known fatalities have ever occurred but there have been instances of starving roaches chewing off skin, nails, hair and callus with painful bites.
Roach swarms can reproduce so quickly that in mere days they can outgrow their food sources and begin to starve. In these instances they will turn to food that normally they would not eat. They are most likely to attack the parts of a human which are already dead, including hair and nails.
German cockroaches have been especially noted as aggressive. They will bite with far less provocation than other species of roach and while not dangerous to humans in the strictest sense, they are a painful nuisance.