That's cool. Our rabbit population goes up and down, I think mostly reflective of the coyote population, but I've always like having them around, even when we had a garden. Rabbits get a bad rap from gardeners, but they're not nearly as destructive as woodchucks and deer. Sure, they get into the flowers and whatnot, but seldom enough to destroy anything. I think more crucial than setting out carrots or anything for them is environment and keeping the cats away. I haven't seen cats get the best of full grown rabbits very often, but they will quickly decimate nests. Their nests are generally very well disguised, so need to watch for them during spring mowings. As far as environment, I removed a dozen or so overgrown junipers 10 years or so ago and we saw a significant drop in bunnies around the yard, but starting planting a few at a time to replace them, trim the bushes low to the ground, things like that so they have places to duck into quickly, and they've come back pretty good.