All genera have two rows of overlapping, keeled scales on the underside of the tail near the base. The upper side of the tail is bushy, and the tip of the tail is often tufted. The fur is silky and usually brilliantly colored. The ears and eyes are large. The digits are well developed and have strong claws.
Males have a baculum.
The molar teeth are longer than they are wide. Scaly-tailed squirrels den in hollow trees up to 40 meters above the ground or sometimes spend the day clinging to the trunk of a tree. Most forms are nocturnal, leaving their retreats soon after sunset in gliding flight from a high level in one tree to a lower level in another tree. Zenkerella, which lacks the gliding membrane, may be active mainly in the daytime. All the scaly-tailed squirrels can run along branches like true squirrels.