I'm not sure when they should go out. Last year we were given duckllings but they weren't "new" like the ones we have now. I'm not sure when I can safely put them out in their house here in the North East (SE CT really). With all of the water we've had lately we're having electril problems in the garage and I don't dare to put a heat lamp in their house because it may just go off in the night and I wouldn't even know it.