I actually started seeing these guys 4 months after I started my tank, and had not added a single thing other than food all along the way. I still have no idea how they got in there other than I did use cycling agent when I first set it up. (hide and seek champs?)
But, yeah, I been able to keep them under control with feeding. These guys are in my lil 6 gallon desktop tank. At one time I was up to 30 visible, and now I can never find more than 3-4
I witnessed the breeding lol. Not sure how rare that is, but I saw what I thought was one just bouncing on the glass, and I thought that was strange...When I looked closer, yep, there was a friend attached lol.