One of the reasons is that the ancients nicknamed the snake "Little Dragon", which means wealth and good luck. If a snake climbs into the house, it means bringing good luck to the house, and it also means that the owner of the house will make a lot of money. If the snake is culled at this time, it will turn good luck into evil, which indicates that there will be great disaster in the family. However, there are always exceptions. If it is a white-gray poisonous snake, the ancients thought it was a sign that someone in the family was going to get sick and should be killed in time.
Another reason is that the ancients thought that snakes appeared in their homes, which was a reflection of their deceased relatives missing their families. At this time, it is even more necessary to respectfully ask the snake to go away, and then wait until you have time to worship at the grave of your deceased relatives and explain to them the recent situation at home, so that the snake will not appear at home again.
The third reason is that the ancients thought that snakes were the patron saint of the family, because they predicted that something would happen in this family, so they came to remind them, which was equivalent to the role of correspondents.
In any case, the snake looks terrible, but as long as humans don't have malice towards it, it won't attack people actively. If you are still afraid of snakes breaking into the house, you can sprinkle some irritating powder around the house, such as sulfur powder. Snakes are very sensitive to this smell and think it is a dangerous signal, so they will not climb into their master's house. In any case, Feng Shui does not recommend killing snakes that climb into the house. If there are snakes in the house, you don't need to hurt them. Prepare a stick, let the snake wind around it, and catch it in a tree pit or grass.
Solemnly declare: the answer is for reference only, please don't be blindly superstitious.