What is the ruling on slaughtering young kittens for fear of their torment due to the absence of their mother, and what is the ruling if some of them are slaughtered due to the presence of their mother, out of fear of their multitude in the house?

Killing animals for which the Sharia has not permitted their killing is impermissible. This is supported by the hadith: "No human kills a sparrow or anything larger than it without just cause, but Allah Almighty will question him about it." It was asked, "O Messenger of Allah, what is its right?" He replied, "That he slaughter it and eat it, and not cut off its head and throw it away." Slaughtering kittens is not permissible if the reason is merely fear of their multitude or lack of food for them, for Allah provides for them. Rather, one should treat them kindly or let them go.