The relationship between a herbivore and the bacteria which live in its caecum is known as

The relationship between a herbivore and the bacteria that live in its caecum is known as "symbiosis." Symbiosis is a close and long-term interaction between two different species, where both species benefit from the relationship. In this case, the herbivore provides a warm and nutrient-rich environment in its caecum for the bacteria to live in, and the bacteria help the herbivore digest tough plant material, breaking down cellulose into simpler compounds that the herbivore can absorb as nutrients. This mutualistic relationship benefits both the herbivore and the bacteria, and they depend on each other for survival.