The big 1 to 2 inch roaches live outside and do need moisture to live. The wood and tree roaches can fly short distances.They wonder into homes and do not live long inside.
Roaches like to hide in the dark corners, cracks and crevices under the cabinets.
Perhaps it's not that they prefer the second floor above the first floor, but they have found an easier entrance to the second floor via walls and piping or maybe where the cockroaches are located, it's more convenient for them to access the second floor bathroom than the first floor bathroom.
Cockroaches not only eat left over food crumbs - they eat pretty much anything. They will eat things like pet food, toiler paper, soap, etc.
Also, maybe it's more humid and warm in the upstairs bathroom than it is on the first floor bathroom. Some breeds of cockroaches enjoy the warm and humid climate in bathroom cabinets to breed.
Sometimes cockroaches will find a way to the upstairs if they were perhaps in a bag you brought home and left upstairs, or had climbed in an object that was taken up to the second floor like a vase, box, bag, etc. and then climbed out without you noticing it was there.
For crying out loud, go buy some roach paste at the hardware and kill the SOB's off. Why are you feeding them? Exterminate. Put that paste everywherte. Buy everything else you can find to destroy them too. UGH!
I have a cockroach problem in my house. I live in a small 2-floor house and a cockroach appears every now and then on the 2nd floor bathroom. We have an open kitchen downstairs and we leave a bowl of food remains on the kitchen sink.
Of all the research i've done on cockroaches, they should prefer darker, damper, and places with lots of food remains. So why the hell are there cockroaches on the 2nd floor bathroom instead of the 1st floor kitchen or bathroom?
