Question....

[Chilli]

Definately not rats. They are social, and two rats would be way too cramped in a 10g... even a 25g. Plus, you would be cleaning the cage like crazy trying to keep up with the mess they would make in such a small place.

Mice are always fun to have around.. especially a small group of females. My current female has a 10g all to herself and she loves it.

And have you checked with the officials at the college? I know you mentioned that they said "aquarium animals only: max 25 gallons." ... but rodents aren't necessarily classified as aquarium animals. Like IRescue452 mentioned, you may have the rodents taken away if you don't get this cleared first.

Best of luck in your decision.

[KittyGurl]

I think hamsters, mice and gerbils can be kept in a tanks. I would get a 25 gallon tank so they could have more room (if you are planning to get a hamster.) The mice and gerbils would be okay in the 10 gallon.

[Hellow]

I keep Little Bit in a 10 Gallon aquarium and he does fine. but he lives by hiself
so that may change things, plus when you only keep one gerbil you have to socialize with them very often which i can do because i only have Reggie as my other pet.