You know, I'm not sure. I suspect they would hatch Thing eggs. We are perfect copies, and that means we can copy those organs, too. In either case, it's better that I not take any of your chickens. However, dead meat will do the same job for less risk.

Things can die, but they're harder to kill than the real versions of the creatures they pose as. Fire, strong acids, and electricity can kill a Thing, but they cannot be shot, stabbed, or poisoned fatally. They can assimilate toxins without being affected by them, simply shifteng into a form that would be unhurt.

Bob comes over and picks up the chicken thigh in his mouth. He swallows, but rather than digest food as a real dog would the chicken is simply absorbed directly into his body and refreshes his cells. Hm. This is pretty good.