Cats make good mothers. They are attentive, protective, and patient. Mother cats prefer to keep their kittens in a safe, hidden space even if they are in their own home. If a mother cat thinks that their kittens are too exposed, they will move their kittens to another location, but why does mother cat move only one kitten? There are two main possibilities as to why they would do this.
Is it normal for a mother cat to move her kittens?
The first possibility is that they were interrupted while they were moving the litter. They might perceive a danger that drew them away from the kittens, or a door or other obstacle was placed in their way usually without their human companions realizing it. If the mother cat returns to their litter and seems upset or agitated or if they show signs of moving the rest of the litter then there is nothing to be concerned about.
The second possibility is more troubling. If the mother cat comes to believe that a kitten is sick or in some way negatively impacting the litter, then they may remove that kitten from the rest and leave it somewhere else. While this is sad, it is a defense mechanism that is intended to protect the rest of the litter. If there is nothing visibly wrong with the kitten, then it can be returned to the litter and it is likely that the mother will simply accept them. If the kitten is acting strange or appears to be ill, then they should be taken to a vet and may need to be bottle fed until they are well. The mother cat may never accept the kitten back into the litter at all, so the kitten may need to be bottle fed until it can be weaned.
You can also consult your vet as to why does mother cat move only kitten. As always, follow your vet’s recommendations. Your vet may provide additional insight.