I bought this for my cats, set it to feed twice a day. There is a door that opens and closes to let the food fall down into the bowl by gravity. Sometimes it works like it should, but most of the time, the food doesn't fall out. I have changed the type of cat food, changed the setting to give more food, only to get the same results. So almost every other day, I have to open the top, shake it, and fill the cat bowl myself. I could not trust this feeder if I went on vacation or was gone for a few days.