This is probably one of my favourite go-to food puzzles! Mainly because its level of difficulty is one you can play around with and make it super easy for your pooch, and through time make it as challenging as it's meant to be.

That's why we think it belongs in our top Ph.D. level! 3 weeks may not be long enough for most dogs, but it's a good start before swapping for another (to give your dog a break, let them miss it a little) and renting it again later on!

At its highest difficulty, you would lock as many of the white pieces as you want and your dog will need to first unlock them in order to move the green pieces with their paw or nose to get to the piece.

The unlocking mechanism is what's going to really put your dog's brain to the test, as not every dog will have enough strength in their paw to pull on them to unlock (you can semi-lock each piece for easier pulling).