Buoyancy the Cat really likes his Hexbug. He follows it around the kitchen, bats it into a corner, flips it over, then curls up around it to keep it from escaping. Then he bats it some more, until it rights itself and gets moving again.
If it goes into the part of the kitchen he doesn't like - by the sink - he picks it up carefully in his mouth and carries it over to the part he likes - by the food bowls - then drops it and chases it again. When he's done with it, he "kills" it by dropping it on the rug, where it can't move anymore.
I think Dubiety mostly just appreciates that it keeps Buoyancy entertained so he doesn't have to.