Why does a rat eat hair? - briefly
Rats gnaw hair to obtain keratin protein and to satisfy a natural urge to chew, which helps wear down continuously growing incisors. The behavior also removes stray fur from nests, contributing to hygiene.
Why does a rat eat hair? - in detail
Rats may ingest hair for several biologically grounded reasons. Nutritional deficiencies trigger pica, a compulsive consumption of non‑food items, when essential nutrients such as protein, calcium, or certain vitamins are scarce. Hair, composed primarily of keratin, offers a minimal protein source that can temporarily alleviate such deficits.
Stressful conditions, including overcrowding, poor sanitation, or abrupt environmental changes, elevate cortisol levels and can lead to abnormal oral behaviors. Chewing on hair serves as a self‑soothing activity that reduces tension and occupies the animal’s gnawing instinct.
Grooming habits also contribute. Rats continuously clean their fur; loose strands may detach and fall into the mouth during this process. In densely populated cages, hair accumulates on bedding and surfaces, increasing the likelihood of accidental ingestion.
Parasitic infestations or skin irritations prompt rats to bite and pull at their fur, producing fragments that are subsequently consumed. This behavior may be a misguided attempt to remove irritants or alleviate itching.
Contamination of food supplies with hair—common in inadequately filtered grain or vegetable feed—provides another ingestion pathway. Rats do not discriminate between edible and non‑edible particles when foraging, especially if the food source is scarce.
Health implications of hair consumption include gastrointestinal blockage, especially when large quantities accumulate. Keratin is indigestible for rodents; it passes through the digestive tract largely unchanged, potentially forming bezoars that impair nutrient absorption.
In summary, hair ingestion in rats results from a combination of nutritional need, stress‑induced oral activity, grooming mishaps, parasitic irritation, and environmental contamination. Mitigation strategies focus on balanced diets, low‑stress housing, regular cage cleaning, and thorough food preparation to reduce the presence of stray fur.