To be honest I thought it was a roach. Kinda got the jump on it so fast that I didn't see it's behaviour
I'd call shenanigans but some one else said the same thing a while ago... that there were spiders in the caves. Old spiders required you to throw a bush to break their web down, and then a mad dash to try and catch it before it built another web. I'm guessing this was not the case here.