I have an aloe vera plant in my house! No, Im not sure they're not hazardous to cats, but I keep it well out of their reach! Ive been trying to kill it, but it hasn't worked!! I dont normally let them have grass, I tried to do the cat grass thing, but they became nausaus and threw up, so they dont normally get grass unless Im fully prepared to clean up vomit! I know its good for their digestive tracks, but it sure does make a mess!! The last time I got some cat grass, I bought the seeds from the store and then just planted them in a little pot of soil I had! Worked really well, grew really fast, didn't take to long for the cats to make a huge mess of it though! They would get on the counter next to the window and tip it over all the time! They really do like it, but I think its more interesting to grow cat nip and let them get into that!!