I noticed some of the pillow moss in my tank had gone brown so i i pushed on it to see if it was holding any water..it was but when i pulled my finger away i noticed very small bugs crawling back into the moss.i imediately pulled the pieces of moss out and thru them away. I noticed just a couple in the cocoa husk..

what are they?

my tank holds two whites.

do i need to clean out all the substrate? will they make my frogs sick?