Craig,
i have also seen moth damage worse than this, but as it has been pointed out, there are several facts we are not sure of, ie the pile content ( i have never known moth / carpet beetle to munch away on man made fibre, is the damaged area underneath funiture, as we know the insect will only live in dark humid areas.
Steve, it was mentioned earlier, to be sure lift the carpet in the affected area, if it is insect you should see the lavea (dead or alive). They look like rice.
as i said in my earlier reply i still believe attempting to remove paint or whatever has been spilt has caused the damge.
Dean