Sparrow's vision

Some birds, such as sparrows, are congenital night blindness.

The habits of dragonflies:

They hover over the pond, or fly back and forth along the stream, scattering their eggs in the water during the flight; Some species fly close to the water surface and lay eggs in the water with their tails. Both Odonata and Homoptera have ovipositors. They use ovipositors to cut the stems and leaves of aquatic plants and lay eggs into the tissues of plants. Some damselflies can dive into the water along the water plants to lay eggs.

Larvae are mostly aquatic, and the age of larvae is generally 10 ~ 15, which varies with species. Many dragonflies have an annual generation of 1, and some species need 3 to 5 years to complete the generation of 1. On rice in southern China, the larvae of dragonflies sometimes shed their shells. This dragonfly has at least two generations a year. When the larvae mature, they climb out of the water, fix them on stones or plants, and then emerge into adults. Some dragonfly larvae are terrestrial. The newly hatched larvae are covered with a film, which is 1 instar larvae. The duration is short. After a few seconds or minutes, the film falls off and becomes a second instar larva. Larvae grow up on small animals that eat water. Some of them live at the bottom of the water, and some are attached to aquatic plants in the upper water, which can feed on mosquitoes. Adults catch insects of the right size as food in flight. Odonata insects mostly fly outdoors. Odonata insects often come out at dusk to prey on mosquitoes, moths, leafhoppers and so on. , is an important beneficial insect.

The habits of sparrows:

Sparrows are very active where there are people. They are very lively, bold and approachable, but they are very alert and curious. Many people build nests in human houses, such as eaves, wall holes, and sometimes occupy the nests of domestic swallows. In the wild, they nest in tree holes. Except in winter, sparrows are almost in the breeding period, laying about six eggs at a time, the incubation period is about 14 days, and the young birds leave the nest for about one month.

Besides breeding and brooding, sparrows are very gregarious birds. Autumn is easy to form hundreds or even thousands of large groups, which is called sparrow flooding. In winter, they will form a dozen or dozens of small groups to move together.