Yes they can. It has to be the large 12" ball as the others are too small for them
maybe for them to run around in
No, depending on the size they run from 5-10$
It means that your hamster has his balls and that's ok.
Yes. If you find the right place. There are hamster balls for people so there must be some for dogs or you can just put them into peoples hamster balls then it should work.
Only male rats have testicles.
Yes, you can.
Rats are a predatory species, they can and will kill and eat a hamster.
It all depends on the breed of hamster. Usually rats tend to be bigger when fully grown than a fully grown hamster. And if its a dwarf hamster the rat is definitely bigger.
depends on the size.if small enough yes it may.*Due the spinal structure of rats, it is unhealthy and possibly damaging for them to be in hamster balls.If you compare the spines of hamsters, gerbils, and guinea pigs to those of rats, you will notice that the hamsters and such allow their spines to naturally rest with a concave curve, matching the curve of the inside of the ball. Rats naturally rest theirs with the opposite curve, it would be unsafe for the rat to be in a hamster ball for an extended period time, especially with the influence to the curvature of its spine the rat's tail would have.
no
yes
no