Cats are predators by nature and they are hardwired to hunt. When they catch a prey animal, they may bring it home as a gift for their owner.
Cats may also bring home dead animals as a way of showing their affection for their owners.
Mother cats will often bring home dead animals to their kittens as a way of teaching them how to hunt. This is a way of passing on their hunting skills to the next generation.
In some cases, cats may bring home dead animals as a way of marking their territory. This is especially common in male cats who are trying to attract mates.
In some cases, cats may bring home dead animals because they are hungry or malnourished.
In rare cases, cats may bring home dead animals because they have a medical condition.
If your cat is bringing home dead animals, it is important to figure out why they are doing it. If it is due to instinct or affection.