Tuco-Tucos: Ctenomyidae

Tuco-tucos are extremely solitary animals and are found in pairs only when mating. The one known exception is the social tuco-tuco, found in Argentina, which lives in colonies. They are diurnal, meaning they are most active during the day, and polyrhythmic, meaning they alternate between short periods of activity and resting throughout the day.

Tuco-tucos build burrows that are an intricate system of connecting tunnels and small caverns. The main tunnel is about 46.2 feet (14 meters) long, about 2 to 2.8 inches (5 to 7 centimeters) wide, and 12 inches (30 centimeters) below the surface. The burrow usually contains a grass-lined chamber for nesting, and several chambers for storing food. At least two species, the talas tuco-tuco and collared tuco-tuco, keep the temperature of their borrows at 68 to 71.6°F (20 to 22°C) by blocking and unblocking their burrow entrances based on sun and wind.

Tuco-tucos use sounds, smells, and touch to communicate with each other. The name "tuco-tuco" is an attempt by native South Americans to express in words the sound that several species of tuco-tuco make when they are giving a warning to animals that invade their territory. The actual sound is more like "tloc-tloc." Tuco-tucos have several other sounds including a deep rumbling noise made by the male when courting a female.

Tuco-tucos have one or two mating periods each year where the female produces a litter of babies. The gestation period, the time they carry their young in the womb, varies from species to species but generally is 100 to 120 days. Litter sizes vary from one to seven babies, called pups. Males and females reach are sexually mature, able to mate, at about eight months. The average lifespan of a tuco-tuco in the wild is about three years.