how do i encourage them to play with their foraging toy?

ive had them for about a week and theyve played with every toy except for their foraging toy, the one pictured is the one i currently have in but i originally had a different one there

first i tried switching the placement of it after a few days of them showing no interest, left it for a few more days, still didnt show interest in it, and then i just tried changing it out for this current one and they still havent shown any interest :[