Hi Guys! I just got my very first tarantula last month which is a very very pretty GBB sling. Today, while I was looking at her enclosure, I found a bunch of small black/gray bugs(video attached) feasting on what appears to be the leftovers of the dubia roach I fed her yesterday. I don't think they are springtails because springtails are white, right? I am not sure if I need to change the substrate now or whether these bugs are beneficial or harmful to my T.. Any response would be much appreciated. TIA!