My experience is only with dogs - and unless feeding a PMR/BARF or other raw diet I wouldn't give a chicken bone of any kind to a dog - but cooking makes the bones brittle. Raw bones are stronger than cooked.
I think I read somewhere that people give rats bones - cooked or uncooked. The marrow is apparently yummy. Personally, I'd probably do uncooked and remove them after a day or so. Something with how rats chew wouldn't allow a bone to splinter like it would if a cat or dog were eating it.