The tubes are only a small portion of the excellent caracal exhibit, and they are connected to the dwarf mongoose/hornbill enclosure. The mongooses have an opportunity to utilize the tubes, and in doing so perhaps either torment/surprise/excite the caracal...but I'm not sure how often the tubes are used.
I doubt it, since I'm sure the caracal won't go hungry if he or she does not catch the mongoose. I think it is more tormenting for the mongoose since they are the ones being stalked every time they enter the tubes!
