Why is my cat suddenly pooping around the house?

your cat has already marked it's territory around the house. where his territory is marked, he is likely to poop. once pooped in, a spot will frequently be pooped on again, so check regularly for feces. he also might be getting old. my dog did that before he died. or it could be the stress from moving finally kicking in, and making him go into full on "mine" mode.