The time it takes for wren eggs to hatch depends entirely upon the species, of which there are 79 known species in the world. The most common form is the House wren. House wrens are approximately 5 inches in length and can weigh up to 12 grams. They eat insects and build stick nests in their territory. The eggs of a house wren can take between 13 and 15 days to hatch and, once hatched, the nestlings remain in the nest for another 15 days. House wrens tend to nest in birdhouses, shoes, holes in walls, woodpecker holes and old deserted nests of other birds. Another common species is the winter wren. Winter wrens are named this because they are normally found in the southern states of the United States during the winter months. The winter wren grows to about 4 inches long and weighs less than 10 grams. The eggs of a winter wren take between 12 and 14 days to hatch and the nestlings will remain in the nest for up to 14 days from hatching. Winter wrens eat berries and small invertebrates, and live in stick nests that are built in cavities and nooks. Carolina wrens can grow to 6 inches in lengths and weigh just less than 20 grams. They eat mainly animals, including insects and spiders, but some even eat lizards, frogs and snakes. They occasionally eat poison ivy and other weeds. They build stick nests while the female lines the nest with soft materials. The eggs of a Carolina wren take up to 16 days to hatch. The nestlings will not leave the nest for 14 days after hatching. Other types of wren include the White-headed wren, the Cactus wren and the Giant wren. Some wrens such as the Cobb's wren, of the Falkland Islands, are restricted to certain parts of the world.
