I think they were meant for dogs originally. One is a round plate with small white 'bone' cases concealing treats underneath. They need to remove the small bones to get to the treats with two difficulty settings - they cracked that in a seconds, but still seem to enjoy 'playing the game'.

Another is a transparent tube, with plate like stoppers in different locations. Each stopper can be pulled out with a string, causing the treats on top to drop to the next compartment. When they reach the bottom (3 different 'plates') the crow gets his food. That also seemed just too easy for them.

We're now looking for more elaborate games to play with them.

Despite all the obvious communication from them, and them being part of our daily life, they are still scared animals and will not get to a arm's length distance. Still, we get what they give, and love them for it. Beautiful entities they are.