Food Grinding Behavior: A Review of Causality and Influential Factors

Simple Summary Food waste from grinding by experimental animals results in excess food scraps in cages, similar to how wild animals gnaw on vegetation and seeds, damaging the ecological environment. Despite food grinding's function being partially understood, its biological purposes and influencing factors remain largely unexplored. This paper aims to review and explain potential causes of food grinding in animals, identify influencing factors, and discuss limitations. It emphasizes recent progress on gut microbiota's significance in food grinding. The findings promote comprehensive food grinding research, benefiting laboratory animal husbandry and ecological protection.Abstract Food waste is a common issue arising from grinding of food by experimental animals, leading to excessive food scraps falling into cages. In the wild, animals grind food by gnawing vegetation and seeds, potentially damaging the ecological environment. However, limited ecology studies have focused on food grinding behavior since the last century, with even fewer on rodent food grinding, particularly recently. Although food grinding's function is partially understood, its biological purposes remain under-investigated and driving factors unclear. This review aims to explain potential causes of animal food grinding, identify influencing factors, and discuss contexts and limitations. Specifically, we emphasize recent progress on gut microbiota significance for food grinding. Moreover, we show abnormal food grinding is determined by degree of excess normal behavior, emphasizing food grinding is not meaningless. Findings from this review promote comprehensive research on the myriad factors, multifaceted roles, and intricate evolution underlying food grinding behavior, benefiting laboratory animal husbandry and ecological environment protection, and identifying potential physiological benefits yet undiscovered.