Brush rabbit the drier seasons while grasses are used in the wetter seasons in relation to growth of annual vegetation. Use of habitat also probably is related to the breeding season. The brush rabbit is smaller than many of the other cottontails, and unlike most of them, the underside of its tail is grey rather than white (which may be why its common name does not include the word "cottontail"). The upperside of the brush rabbit's fur varies from light brown to gray in color, while the underside is usually always white. Adult rabbits measure anywhere from 10–14 inches long and rarely
Rabbit than fact in modern times. In other parts of Britain and in North America, invoking the rabbit's name may instead bring good luck. "Rabbit rabbit rabbit" is one variant of an apotropaic or talismanic superstition that involves saying or repeating the word "rabbit" (or "rabbits" or "white rabbits" or some combination thereof) out loud upon waking on the first day of each month, because doing so will ensure good fortune for the duration of that month. The "rabbit test" is a term, first used in 1949, for the Friedman test, an early diagnostic tool for detecting a pregnancy in humans.