Mucus has two functions, it moistens the body surface and protects it.

The columnar epithelial cells on the body wall of earthworms are interspersed with glandular cells, which are divided into mucus cells and protein cells that can secrete mucus to moisten the body surface. When earthworms encounter violent stimuli, mucus cells secreted a lot of wrapped body into a mucus membrane, has a protective effect.

Expanded Information:

Earthworms have been known to grow and develop in a variety of ways. p>The growth habit of earthworms:

1, like darkness

Earthworms are nocturnal animals, hibernating in dirt burrows during the day, and going out at night, generally from 8:00 p.m. in the evening in the summer and fall to about 4:00 a.m. the next morning to go out, and it is in the dark foraging and mating.

2, like moisture

Natural terrestrial earthworms generally like to live in the moist, loose and rich in organic matter in the soil, especially fertile gardens, vegetable gardens, cultivated land, ditches, rivers, ponds, channels, as well as near the cafeteria near the side of the sewer, garbage piles, water tanks under the place.

3, like quiet

Earthworms like quiet surroundings. Life around the mines and industries of earthworms more poor growth or escape.

4, like warm

Earthworms, despite the worldwide distribution, but it likes a relatively high temperature. Below 8 ℃ that is to stop growth and development. The optimal temperature for reproduction is 22 to 26 ℃.

5, sweet and sour

Earthworms are omnivores, it is in addition to glass, plastic and rubber do not eat, the rest of the humus, animal feces, soil bacteria, fungi, and the decomposition products of these substances are eaten.

Earthworms have a sensitive sense of taste and prefer sweet and sour flavors. Aversion to bitter flavor. Prefer to heat the fine soft feed, especially for animal food gluttony every day to eat food equivalent to their own weight. Food passes through the digestive tract and about half is excreted as feces.

6, like to live alone

Earthworms have the habit of not wanting to live with the mother and child. Especially in high-density situations, the small ones reproduce more, the old ones have to run away and move.

7, photophobia

Earthworms are negatively phototropic, especially to avoid strong sunlight, blue light and ultraviolet radiation, but not afraid of red light, tend to weak light. If the cloudy and humid morning earthworms out of the burrow activity is this reason.

The toxic effect of sunlight on earthworms is mainly due to the ultraviolet light contained in sunlight. According to the sunlight exposure test, earthworms for sunlight irradiation 15 minutes 66% death, 20 minutes is 100% death.

8, fear of shock

Earthworms like a quiet environment not only requires low noise, and can not vibrate. Near bridges, highways, airports near the earthworm farm should not be built. After the vibration, earthworms show uneasiness, escape.

9, fear of immersion

10, fear of salt

11, fear of spicy

12, fear of hot and cold

Baidu Encyclopedia - Earthworms