Titmice nest in holes in natural tree cavities, or ones they excavate or borrow from woodpeckers and other birds. (This is why it is important to retain dead trees in a woodlot). They build their nests within these cavities or a birdhouse of bark, leaves, grass, hair, cloth, string or nesting materials you leave in the yard for them. Titmice mate for more than one year. Typically they lay one clutch of 5 to 8 eggs per year from early May to late June (North) and late March to mid-June (South). After a 12 day incubation, males help raise the brood. They live from 3 to 12 years.
Titmice prefer manmade accommodations that are 4 inches square at the base and 8 to 10 inches high. The entrance hole should be no larger than 1¼ inches in diameter, located 6 to 8 inches above the floor of the box. There should be no perch. This will discourage predator birds from raiding the nest. Mount the house between 6 and 15 feet above the ground. This is a bigger range of nesting heights than most birds accept. For examples of bird houses for titmice, go to Yardener\'s Tool Shed bird section