"bugs"

so i have seen something new in my many years of aquascaping

i have these bugs in my tank i haven never read about or seen them before
they look kinda like ladybugs but there a brownish to light brown kinda
some have small back speckles and they are slightly smaller than ladybugs\
they are very fast and they proliferate at amazing speed

the tank is perfectly healty but since im in iraq i dont have any fish being that i cant find a dealer to send them over here. the only inhabitants are red cherry shrimp i do know that if i had fish they would prob get eaten. so much for that idea...
do you knwo what they are?
too bad i dont have a picture

are they harmful to the tank?
if so what will they do?
and how do i get rid of them?

are they good for the tank?
if so in what way?

how do i fight them off hmmm :fencing:
if you can help i thank you in advance

sorry i didnt know what forum to put this in but since the aquascaping section gets lots of attention i figured id drop it in here.