wood rat: any of various small short-tailed rodents of the northern hemisphere having soft fur grey above and white below with furred tails and large ears; some are hosts for Ixodes pacificus and Ixodes scapularis (Lyme disease ticks)
rodent: relatively small placental mammals having a single pair of constantly growing incisor teeth specialized for gnawing
theory of dissociation: (chemistry) theory that describes aqueous solutions in terms of acids (which dissociate to give hydrogen ions) and bases (which dissociate to give hydroxyl ions); the product of an acid and a base is a salt and water