Light to dark cycles in indoor wildlife housing should be controlled by:

• A. Light left on all day
• B. Left on during the day the same number of hours as outdoors
• C. Random
• D. Left on only at night

Answer: (B)

Matching light–dark cycles to the natural day length is essential for wildlife in indoor housing because circadian rhythms rely on consistent daily cues to regulate activity, feeding, rest, and hormones. The best approach is to keep daylight hours equal to what the animal would experience outdoors for the current season, giving a regular period of light followed by darkness. When lights stay on all day, the animal loses a true dark phase, which can disrupt melatonin and cortisol patterns, alter behavior, impair sleep, and increase stress. A random lighting schedule introduces unpredictability, which also disrupts rhythm and can be stressful. Lighting only during the night would invert the cycle and confuse the animal’s internal clock. In practice, adjust the indoor photoperiod to mirror outdoor daylight for the species and season, and consider gentle dawn and dusk transitions to smooth the change.