Of the animals that the USDA collects numbers on, 1,438,553 were used in research in 2002.*Since more than 1.4 million mammals other than rats and mice were used in research, and since mice and rats probably make up 90% of the animals in labs, we can guess that about 14 million rats and mice were used in research in 2002.* In labs, small animals, like hamsters, rats and mice, are usual kept in cle