The Jack Russell Terrier is named for Reverend John Russell, a nineteenth-century Devon parson whose white terriers kept pace with hounds and bolted foxes from their dens. Most Jacks stand 10 to 15 inches tall and weigh 13 to 18 pounds, with mostly white coats in smooth, broken or rough textures and black or tan markings. That compact size suits Trenton's narrow rowhouse blocks, but the working instincts come along with it.
Many Jacks are bold, quick and funny, with a strong prey drive and a talent for climbing, digging and slipping through gaps. They do well with active adopters who enjoy training games, and they rarely settle for couch life. With squirrels, pigeons and busy sidewalks around, a secure harness and a reliable recall cue make daily walks easier, and sniffing games add mental work when weather limits time outdoors.