I have wo female rats and an eleven inch wheel and they wont run on it why?
Well Rats are like people, they have varied interest. I have three rats. Two use it during the day to nap in and one runs all night and the others, even when she has been out, have no interest in running on it. The other thing is, it might not be big enough, check up on that. Leave it there though, they can use it to sleep on, they like that.
Every one of these little guys has a unique personality. Most rats I've known aren't interested in wheels I've often removed the wheels from their cages in order to give them more room for climbing other activities. On the other paw, a few of our females have been interested to *some* degree in using a wheel, even when they've had an entire room to explore. While most of these girls were happy to give the wheel a couple of spins then jump off, our hairless girl *loves* her wheel actually holds her tail in a curled position much of the time (this is called, appropriately enough, 'wheel tail' is kind of cute). What really impressed me though, is our hairless *taught* another girl to use the wheel! They don't just run on it, either-- they bounce, rock 'dance'.
Make sure that your wheel has a solid bottom. If its the kind with bars, their tails could get caught. Rats' tails are made of bone, so their tails could break. In my experience, rats seem to prefer climbing and burrowing to running on a wheel. Also, I don't know if its true, but I heard that if a rat runs on a wheel too much it can hurt her back.
