1. Plural, for rat
2. A group of small animals, rodents. Tend to dwells in the sewers. (Sewer rat).
2. An expression of discontent. See also damn
1. Pied Piper: "Damn, where'd all these rats come from?"
2. "Rats!" Johnny exclaimed, when he discovered he'd shot the wrong person.
3. After several smelly farts, and downing a package of ex-lax pills, Bobby realized that it was time to feed the rats.