I wanted to know if a baby squirrel could stay in the same 4-floor cage as a pet ferret or bunny we were thinking of adopting or buying. I also want to know if the baby squirrel might attack or anything, and we are not keeping the squirrel for long. we are just going to care for him because he's an orphan and his mom was killed by stray cats in our area. my last question is if we should turn the squirrel to animal control. I asked many people and a few said that they'd kill him.
So you never want to mix species in the same cage. Ferrets are in the weasel family and are natural Born Killers. They WILL kill a squirrel (baby or adult, as well as birds,bunnies, rodents etc...) Also, bunnies are a little territorial. Even if you have the sweetest bunny, an accidental kick from their strong back legs could do some major damage to your rescued squirrel. The other concern is that wild animals and caged animals have a different tolerance to sickness, bacterias and fungi. Your squirrel may have been exposed to something that could make another animal sick, if exposed by close encounters, urine and decal matter, or other bodily fluids (sneezing or sharing drinking water, etc). Even if your squirrel is healthy it doesn't mean he hasn't been exposed to something it's tolerant of that other caged animals have yet to build antibodies towards ridding off.
Try looking up a wildlife rescue or a squirrel rehabber in your area. They will be more informed and more likely to care for and re-wild the squirrel than animal control.