Fun, easy, inexpensive! This foraging toy by Doc & Pheobe is adorable. It is a great beginner toy for cats to learn the upward motion of tipping things for the food to dispense which is a challenging move for some cats to learn. The feathers really add interest. One could always cover up a hole to increase the challenge or place objects inside to make it more difficult for the food to dispense.
If your cats "scarf and barf" this food puzzle is for you! A cat's stomach is quite small, about the size of a ping pong ball, so when they eat too quickly, vomiting is often the result. Slow feeders like this one help make the meal last a little longer.