I think I have only 1 scud left in the indoor tanks. I've never seen more than 1 at a time for the past couple months. Just before that I had a number of them in the 3 gal tank and they seemed to be mating, but maybe they were eating each other. I've never seen any in my outdoor ponds except for 1 I saw swimming under the ice a day or two after I stocked them in my small garden pond.