Both can end up in the walls of a 3rd floor apartment.
Do Rats Climb Walls. But they are quite a heavy animal (230g) and so gravity is a also wall cavities are safe from predation and dark 24/7 meaning that rats can fully use their nocturnal senses. Rats in the walls of your home are especially hard to drive out, without resorting to tearing down the house.
2 Tricky Ways Rats Get In To Your House - Venus Pest Company from www.venuspest.com
Norway rats are known to be much slower, larger in size, and less rats, in general, cannot climb smooth walls or glass. Black rats are good climbers and will happily inhabit lofts. Rats can easily climb pipes, rain spouts, cables, and other vertical objects where holes can provide an entrance to your home.
The animal could have easily got away and crawled pet store rats (fancy rats) do not carry mycoplasma.
You'll know where to set these traps if you find scratch marks on wall insulation and other surfaces near openings or cracks. The wall cavity will be open within the roof void therefore. Research your facts before you state things that are opinion and not fact. That's your rat checking things out.
