Agouti:

Variations of a gene. Altricial:

When a rat pulls out his own fur the fur of another rat. Benign:

Abbreviation for black-eyed-white, a variety of rat that results from white marking genes. Bruxing:

Male rat. Carcinogenic:

Most active at dawn and twilight. Culling:

Female rat. Dominant:

Variety of rat that has ears placed more on the side than the top of the head. Ears also are shaped differently than standard rats'. Exotic:

Cells that contain only 1 set of chromosomes (regular rat cells contain two sets). Sperm cells and egg cells. Gene:

The genes that make up an organism. Gestation: