The frog in the well refers to a frog.

Frogs belong to the amphibians of the Phylum Chordata, Class Amphibians, Order Anura, and Frogidae. Adults have no tails. Their eggs are laid in water, fertilized outside the body, hatch into tadpoles, and breathe with gills. After mutation, they become adults. Breathing mainly through the lungs and through the skin. There are teeth in the upper jaw, usually vomerine teeth. The shoulder girdle solidifies the chest, the vertebral bodies are staggered, and the transverse processes of the sacral vertebrae are columnar; there is no intervening cartilage between the two joints at the ends of the fingers and toes. The tympanic membrane is obviously hidden under the skin, and the skin is smooth or has warts. The tongue is generally long oval, and the back end is mostly notched.

Extended information:

Frogs often inhabit rivers, ponds, rice fields, etc. They mainly move in the grass near the water, and sometimes they can also lurk in the water. Most of them are active at night and feed on insects as their main food. They also eat some snails, snails, shrimps, small fish, etc. Most of the insects they eat are agricultural pests. Some people estimate that a frog can eat 70 bugs a day and eliminate 15,000 pests a year.

Frog is an animal beneficial to agriculture and should be protected. When the weather gets cold in late autumn, frogs hibernate at the bottom of the water or in caves, and return to the water to breed when the weather warms up the following spring. During the breeding period, many male frogs often gather in the same area and chirp loudly and continuously. This is the so-called "frog pit."