My setups

Tanks are by no means acceptable living conditions for rats They should only be used for young litters, or ailing/recovering rats. A 20 gallon tank isn't even large enough to hold one rat, let alone 2. And a 10 gallon should never be used for any reason.

If the grids you're talking about are the Organize-It cubes, than yes, the holes are very large. Even my adult males could get their whole heads through the wire spacing.

Check out Martin's Cages. For three rats, I would suggest the R-695.

Honestly, why did you get rats if you can't afford proper housing?

Actually, I'm not attacking you in the least. I just don't understand why you didn't get proper housing BEFORE purchasing the rats. You need to have everything setup and ready before your new animals come home.

Since when do proper rat cages cost $200? For a good-quality cage from Martin's Cages that can fit up to 6 rats, you're looking at only $120.

Why ignore me? All that I'm saying is fact. Go ahead and look up everything I'm saying if you'd like. Go to Martinscage.com - there AREN'T any $200 rat cages. Google "rat cage calculator" and put in the dimensions for both a 20 gallon and a 10 gallon - neither are large enough for the rat(s) you have in them. In fact, just in case you don't feel like looking up a cage calculator, I'll do it for you.

For a 20 gallon, you can only fit one rat in it.
For a 10 gallon, I get the result, "This cage is too small for an adult rat."

You just choose to ignore me because I'm telling you you're doing something wrong. Although I'm right, you'd rather just pretend to not hear it.

Okay, everyone who's flipping out over this is insane. Simply because I mention someone's doing something wrong, doesn't mean I'm attacking them.

Seriously, grow up.

Moreover, it's not as though anything I'm saying is judgmental or pure opinion. I'm stating facts.

If you absolutely must keep your rats in a tank, make sure it's a 50 gallon or, preferably, larger. Ten or twenty gallon tanks are too small to house any rat, and should only be used for ailing/recovering rats.