I've been using the silca litter perls for a couple of months now (though am no means an expert!) So far, my ferrets haven't had any problems with them. I haven't heard of any problems with other people so far, and would like to hear if problems did exist. I was a bit leary when starting out (but do to a mixup they were free, so I had to give it a chance). The perls *love* to bounce around, and in a shallow litter pan they went everywhere. When I started cleaning up, I noticed some of the perls would stick to my fingers and was worried that they would stick to the ferrets. When I checked the ferrets over, one did have a perl stuck to the tip of their nose, but they wiped it off on their bedding towels. Haven't seen it stick anywhere else though. Just the occasional one on the nose right after I change the litter. Seems my ferrets have to roll around and nose through it after it gets changed. I started mixing in a couple of scoops of "dirty" perls when I change it, so they won't be so inclined to play. In the few months we've been using it, my boyfriend and I both love the stuff. It does cut way down on the smell (which makes my boyfriend extremely happy). It is slightly more expensive than other stuff out there, but my boyfriend doesn't paying a little more for it. If you do happen to buy it, we've learned a trick to getting it cheaper. There are a couple different "brands" of the perls. Litter Perls and Litter Secrets (I think that's the different names). It turns out Litter Secrets is just bulk bought Litter Perls sold at a lesser cost. One bad thing about the stuff is it can get messy when it's time to change it. I must not distribute the perls around enough when I'm taking out the solid waste, because at the end, I get a lot of saturated stinky perls stuck to the bottom of the pan. I could probablly dump a new box (or a half box, which is what I use at one time) on it, but then I feel I'm being a bad mommy so I sit there and clean it out. On another note, we took our fuzzies to get their rabies shots this weekend. It was an outlaw clinic weekend here in CaCa land, and it was nice to get to meet with other ferret owners. Nigel didn't enjoy the outing though. He got stuck wrong with the shot and bled a little, so he had to get cleaned up with an alcohol swab which he did not enjoy. Spent the rest of the time being very mellow in our arms. No other reaction tho, thank goodness. Sebastian, the "baby" who had given us a scare right after we first got him by losing 40 grams between vet visits, is now bigger than Nigel. He greatly enjoyed the outing, except for the shot of course. He was extremely hyper and had a lot of fun playing with the other ferrets in make-shift playroom. Rowan [Posted in FML issue 2933]