A few treats in a Kong® for dogs or a Pipolino® for cats will get the brain working! Your companion will rack his brains to get them and will quickly become smarter with each new experience. However, be careful not to play too often or let the game last too long, otherwise it will become torture, especially when he is hungry!
You can also make these little toys yourself: in a shoebox with a pierced lid, your cat will have to put his paw inside to get the kibble out. For dogs, remove the cap from a small plastic bottle and put treats inside: he will have to tip the bottle over to get them.