Here are some:
-Syrian (teddy bear) hamsters can live in a crittertrial/habitrial (or equally small) cage.
A syrian hamster should ONLY be housed in a cage with a minimum floor space of 29 ½ inches x 15 ¾ inches x 15 ¾ inches. That means absolutely NO crittertrial or habitrial cages.
-Goldfish (or any fish for that matter) only grow as big as their tank.
The reason this "fact" came about was because, while the fish does slow its growth down considerably when housed in a smaller tank, it doesn't stop. The stress levels of the fish. caused by its slowed growth rate and inadequately small tank, will exponentially grow until it causes the fish's death. Therefor, goldfish should be housed in the proper sized tank to avoid this issue.
-Hamsters can't be housed in a glass aquarium due to the circulation problems.
If you clean out the tank on a regular basis, its more than suitable for a hamster, providing that its big enough. A 20L is the minimum sized tank any species of hamster should be housed in, including dwarfs. In actuality, a tank is ideal for the smaller dwarf species as they don't have bars that the hamster could escape through.
Hamsters are actually very clean little critters who have no natural smell. Its their waste that smells and the accumulation of which due to a negligent owner causes their cage to smell horrendously. If cleaned out properly on a regular basis, there is no smell at all.
Well, that's all I can think about for now. I might come back later with more.
Last edited by TheCrabbyTabby; 09-06-2012 at 05:46 PM.