Alongside the Bloodhound and Basset Hound, the beagle has one of the best developed senses of smell of any dog. In the 1950s, John Paul Scott and John Fuller began a 13-year study of canine behavior. As part of this research, they tested the scenting abilities of various breeds by putting a mouse in a one-acre field and timing how long it took the dogs to find it. The beagles found it in less than a minute, while Fox Terriers took 15 minutes and Scottish Terriers failed to find it at all. Beagles are better at ground-scenting (following a trail on the ground) than they are at air-scenting, and for this reason they have been excluded from most mountain rescue teams in favor of collies, which use sight in addition to air-scenting and are more biddable. The long ears and large lips of the beagle probably assist in trapping the scents close to the nose.