A dog that normally scores above 80% on recall, is suddenly struck deaf to all sounds in the world, except maybe squirrel ones.
A dog who is normally super motivated by a 6 letter word "c-o-o-k-i-e" could care less about the them and only wants to eat one thing, squirrel.
The dog chases a squirrel and/or waits at the bottom of the tree for the squirrel. The dog may try to climb the tree. The dog only sees the squirrel (squirrel blindness).
This seeming paralysis lasts until:
1) they catch the squirrel
2) by some miracle they appear to realize they can't catch the squirrel and perhaps your cookie isn't the worst thing in the world. (At least they don't have to climb a tree to get it!)
Black dogs can jump if it is to get a squirrel!