Overview and Meaning
In response to a threat an animal will either submit or flee, to indicate it's subordinate status; or it will challenge the threat with aggressive behaviors. Often the first challenge, by the recipient of the initial threat, will be an aggressive bite.
Escalated aggression, as the name implies, occurs when neither animal backs down and the interactions increases in intensity to become fighting.
Mediated aggression normally represents the vast majority of mouse agonistic interactions, and is widely misinterpreted in the literature. In contrast, Escalated aggression occurs when a subordinate responds to a threat behavior with an aggressive behavior, most typically an aggressive bite. Escalated aggression, as the name implies, escalates until one animal shows flight and submissive behavior, or, in a worst-case scenario, is killed or castrated. (Male mice attempt to castrate each other when they fight, and consequently withdraw their testicles into the body cavity during aggression).