Although I wouldn't volunteer as a subject for such an experiment, it is doubtful that this spider or any other, for that matter, could or even want to bite through denim. Firstly, they are all quite shy and non-agressive, biting only when forced to in their own defense or when cornered or startled. Secondly, their fangs, or chelicerae are only about .04 inches long and therefore aren't capable of piercing most clothing....