How to make budgerigar breeding nest box?

A wooden box of 18cm× 18cm× 20cm (length× width× height) can be nailed with a board with a thickness of 2cm, and the wooden box is divided into two layers at two-thirds of the height in the box, and the lower layer is used as an incubator, and then a circular hole with a diameter of 5cm is opened at one end of the partition to make the incubator communicate with the upper part of the nest box. An entrance circle L with a diameter of 5 cm should be opened on the upper side of the nest box, and an 8 cm wide perch board should be installed below the entrance hole for birds to enter and leave the nest box. The ground of the brooding nest should be made of rough wooden boards with a thickness of 3 cm, and a circular groove with a diameter of about 7 cm and a depth of 1.5 cm should be dug in the middle for birds to hatch eggs. It is best to make the side or back of the recess into a movable door that can twitch up and down for easy observation. After the hatching cage is made, part of the cage bars on one side of the cage can be taken out and the breeding nest can be hung on the cage (the entrance and exit L face into the cage, and the perch board also extends into the cage). In winter, the nest should be padded with sawdust or other soft bedding to keep warm, and in summer, the nest box should be ventilated.