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How are laboratory rats and fancy rats different from wild brown rats?

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black-tailed prairie dog — rodent Black-tailed prairie dog (*Cynomys ludovicianus*).

Laboratory rats and fancy rats are both domesticated forms of the brown rat, yet they differ significantly from their wild counterparts in both appearance and behavior.

Behavioral Differences

While wild brown rats are known for their aggressive nature and adaptability as an invasive species, domesticated varieties have been selectively bred for different traits:
* Laboratory rats: These were the first mammals domesticated for research and are noted for being significantly more docile than wild brown rats.1
* Fancy rats: These are kept as pets and have been specifically bred for gentleness and docility.1

Physical Differences

Domesticated rats exhibit a wider range of physical characteristics compared to the standard gray or brown coat of the wild brown rat:
* Laboratory rats: Often appear as albinos, characterized by white fur and red eyes.1
* Fancy rats: These are typically smaller than wild brown rats and display diverse coat colors and patterns, including blue-gray, white, and spotted varieties. Specific varieties include the rex (curled fur and whiskers), the dumbo (large, low-set ears), and hairless rats.1