Actually it is an 81mm mortar. You can tell by the fact that it has a shorter bipod on the front, no crank handle on the left side of the crossmember and a smaller baseplate. The marines kept us up all night long popping off outgoing. As far as camel spiders go, they won't chase you unless you piss them off. The large mandibles are used for crushing insects such as scorpions, and the will only bite you when provoked. I am looking at one right now that we put in a urine specimen cup filled with alcohol, after one of the other medics woke up screaming with it on his chest, and we speared it with a 14G 5.25" angiocath. The largets one ever recorded was about the size of a mans hand, and I walked up to one the other day that was running across the floor of a B-Hut and stepped on it. So take from this what you will.