what he is trying to say is that if there is snow laying on top of the ground (soil, earth, dirt, grass, whatever) the deer will eat the snow to gain their water supply rather than go to standing water such as a stream, river, pond, pool, creek, lake. hope that covers all the bases. Personally i wouldn't due to the large amount of noise created and the fact that deer if wanting that water would keep a spot cleared no matter how cold it was.