In addition to the above reasons, cats may also lack pets or find a suitable adoptive family in the surrounding environment. For many unsterilized cats, the fertility may increase rapidly, and when their fertility rate is out of control, the possibility of being released to the outside will increase.
Therefore, when a cat appears at your door, please be familiar with it and be vigilant to judge the situation of each cat. If you have the ability and will, find a place to hide them, find or make a safe shelter. If you don't know how to deal with them, please contact the local pet rescue organization or the local city animal control service center for help as soon as possible.