Automatic cat feeders are either battery or plug-in powered devices that hold and distribute cat food at certain times of the day. Similar to an automatic coffee maker, automatic cat feeders have programmable settings for cat owners to customize meal time. Feeders with a tank have a timer inside the feeder that causes a door to open and dispense a set amount of food from a container into a bowl below. This little door shuts once the pre-programmed amount of food has been allowed to fall into the bowl and secures the remaining food in the container. Other feeders have a round tray design, with several small compartments and lid that's open to just one compartment at a time. At the set time, the tray rotates to the next compartment. Both designs prevent your cat from getting to the food and helps keep the food fresh until meal time.