||Motor Patterns of Defense||Page 15|
A motor pattern apparently associated with defense was described by Calhoun [1962, p 33] under the name "burrow-sealing." In response to air drafts or social stress and during a state of lactation, wild rats will push materials into the opening of the burrow in order to seal the entrance. We have observed the same behavior by lactating rats in the laboratory who seal a small door by pushing chips into it after having been disturbed by another intruder rat. A similar and perhaps equivalent motor pattern has been described by Pinel and Treit  who observed that a rat will push bedding material over a shock prod after having been shocked by it.
Specific pheromones are probably secreted as a motor pattern of defense in muroid rodents. There is a secretion of the preputial gland into the urine of M musculus which is elicited by shock and which potentiates fighting in other conspecifics [Mugford and Nowell, 1971c]. A number of authors have shown that defensive animals may be discriminated in terms of their odor [Müller-Velten, 1966; Valenta and Rigby, 1968; Carr et al, 1970]. Defense pheromones may be broadcast by the urination and defecation which may accompany defense in muroid rodents, as described in Peromyscus sp var [Eisenberg, 196]), R norvegicus [Brady and Nauta, 1953; Galef, 1970b], and M musculus [Smith, 1972].
Hormones may be secreted by endocrine glands as a motor pattern of defense. In particular, the adrenal medulla may be activated to secrete epinephrine [Hucklebridge and Nowell, 1974], and the pituitary-adrenal system may secrete ACTH and corticosteroid hormones [Bronson and Eleftheriou, 1964]. Although the phenomenon has been studied primarily in laboratory strains of M musculus, there is at least indirect evidence that it occurs in most muroid rodents [Christian, 1975].
Several motor patterns occur as a response to being attacked by a familiar conspecific and will be discussed under the section on submission. It is possible that these motor patterns, which include crouching, full submissive posture and "piping" vocalization (usually ultrasonic), may occur during defense against predators or unfamiliar conspecifics, but the relevant data are not yet available.