In the summer, I can't see too far into my woods or as easily thru the tree lines ... but in winter, I can see much deeper. But regardless ... often, I see "pieces" of critters ... 10-15 splotches of the critter moving thru the woods and sometimes I can get an idea of the size and sometimes not ... just by continuing to watch ... but I can't shoot it until it comes out into the open somewhere, because it might be one of my cows (or a deer, still a NO SHOOT at night) !! They do move thru the woods sometimes.
But even if thermal isn't perfect ... it is way better than NV. My PVS-30 is hardly usable unless there is a big moon up in the sky signing down into the woods. But otherwise, the illuminator just bounces off the vegetation and makes it harder to see.
So be glad thermal can do what it can do.