Sickness

Villagers in, Animal Crossing: Wild World, Animal Crossing: City Folk and Animal Crossing: New Leaf can become sick, which causes them to shiver (and sometimes show the 'depressed' emotion) and stay in their houses. Villagers can gradually be recovered from being sick if they are given medicine from Tom Nook's shop or the Nookling Stores once a day. Sickness usually lasts for three days if medicine is given every day, but this can vary slightly. While villagers are sick, they will not react positively and a new option appears at the top of the interaction menu, "Need medicine?", sometimes along with "Are you OK?". Selecting the medicine will not give a positive response if the player has no medicine in the pockets but will open the pockets if he or she does. After receiving medicine, the villager will thank the player. After the sickness passes, the villager will give the player an item the following day (or in a letter) if the player took care of the villager while he or she was sick.

In, villagers may inform the player if another villager is sick or thinking about moving away.

Glitches associated with Sickness
In a sick villager is instantly healed; when the player open the town gates. In, the villager will lock his or her house, leaving a sign saying that he or she is feeling ill.