I think they are fascinating.
One day, in a house we were staying on a small island, there were little piles of debris on the windowsills, corners, and various places when we woke up. I looked closely and each pile was being made by ants cleaning their holes....there were little bits of twigs, insect parts, etc. OK, fine....
we went to the place on the island where we were working on a project, and guess what...SAME THING!!! It was ant cleaning day!!!!
I always wondered if they did the same thing the next year, or what triggered it....it was miles between the two locations. they were doing it on the beach too.....so weird.
Its also incredible when they make ant bridges.
ETA: I dont find them fascinating in the house however.