Thanks Callie - I am one of the respondents and am pleased that you did post up the results to share with us. It makes interesting reading.
I was interested to know how many others did things like hide food to encourage foraging. I have tried this before - with my cats, but they look disdainfully at the 'muck left about' and will not touch unless food is properly presented, in a clean dish, in their (nursery) or my dining room.
I was also interested to see how many others used the treat ball. My lot were offered an empty loo roll with the ends loosely sealed up so that treats would spill out if the thing was rolled. Once again, they were more pleased with rolling the thing about than picking up the treats but even then, they got bored of it so I had to take it away and offer them something else.
... and yes, I do rotate the play items so that they occassionally have some in the draw whilst others are out for playing with.
Some things work for some cats and not for others.
I hope the survey helps with your studies - let us know how you get on Callie.
Best purrs.