This article is from the WSSF 2015 AFRMA Rat & Mouse Tales news-magazine.

Did You Know?  Studies done with guppies kept under pink fluorescent light produced more females (80%) than males (20%). Chinchillas housed under incandescent light produced mainly male offspring but when the lights were changed to blue lights, they then produced mostly females.

Mice housed under pink light caused unthrifty young, shorter breeding lives, smaller litters, and shorter life than seen with natural or white light.

Albino rats will have retinal degeneration within 3–7 days when exposed to high light intensities which then causes increased stress.

Continuous exposure to dim light (no dark cycle) is phototoxic to rats.

Intensity of lighting prolongs the estrous cycle in mice and rats. With longer light cycles, the estrous cycle in rats changes from the normal 4 days with 12 hours light/12 hours dark, to 5 days with 16L/8D, to becoming irregular with 22L/2D and will not reproduce.

Rodents do not see red light but continuous red light induces persistent estrus in female rats.

Male mice housed in continuous light for one week fought more.

From Planning and Designing Research Animal Facilities Editors Jack R. Hessler, Noel D. M. Lehner.