B. pacificus probably eats a similar array of prey items. Normally active at night, and return to cover during daylight. Surface activity is limited by extremes of temperature and unfavorable moisture conditions. Egg sets have been found from December 8 to January 18. The number of eggs per set ranged from 13 to 20.
Hatchlings emerge during winter and early spring.
Potential predators include spotted and striped skunks, raccoons, ringtails, gray foxes, ringneck snakes, and various skinks. Los Angeles Co. Mus. Hendrickson, J. R. 1954. Ecology and systematics of salamanders of the genus Batrachoseps. Jennings, M. R. and M. P. Hayes.