What are some facts about armadillo biology and life cycle, such as how many young do they have?

The armadillo is active primarily from twilight through early morning hours in the summer. In winter, it may be active only during the day. The armadillo usually digs a burrow 7 or 8 inches (18 or 20 cm) in diameter and up to 15 feet (4.5 m) in length for shelter and raising young. Burrows are located in rock piles, around stumps, brush piles, or terraces around brush or dense woodlands. Armadillos often have several dens in an area to use for escape.

The young are born in a nest within the burrow. The female produces only one litter each year in March or April after a 150-day gestation period. The litter always consists of quadruplets of the same sex. The young are identical since they are derived from a single egg.

The armadillo has poor eyesight but a keen sense of smell. In spite of its cumbersome appearance, the agile armadillo can run well when in danger. It is a good swimmer and is also able to walk across the bottom of small streams.

Resources: (online)
Armadillos