Uh-oh, that's hella creepy. They will test it by throwing/rolling in a pebble or pinecone (or whatever they can find nearby) and an apple because they're ought to be running low on peaches at this point a peach (let's just say they took an assload of peaches along because it's funnier). Seeing what happens to it, they will absolutely not be touching or getting any closer to the barrier and instead follow it toward the north for a bit, then turn back eastwards, hopefully eventually ending up on the other route they could have taken!