Yes it is.
They eat snails like this, by running up on them, and eating them straight off the branch or whatever.
I have seen them do grasshoppers on screen this way as well.
Grashopper feet can actually grab small things, like screen wire, and their legs will rip off when you try to remove them. If they cant shoot it off, or if a feeders too close to shoot, they will just eat it off the surface.