The reason why a dog suddenly pulls into the nest may be because he wants to retaliate against his owner, attract the owner's attention, occupy the territory, is in a bad mood, is in estrus, etc. The reason needs to be determined based on the specific situation of the dog. It is best to walk the dog regularly to help the dog develop good habits, which can prevent the dog from pooping randomly. Also, do not feed the dog too much at night, otherwise the dog will not be able to hold it in in the middle of the night and will defecate at home.