Yeah its seems they are eggs What u have in your tank?
no, the eggs aren't black, they're white. and they should be in some sort of hard slime... abit like frog spawn but not loads of seperate eggs and the nucleus being white.
this is a minging picture but this is what these snail eggs look like out of the water.
personnally, if they were snail eggs, i'd destroy them and buy, temperarily if not permanent, a snail eating fish.
Any loaches (except khulis, well maybe even khulis) will kill and devour snails like crazy (1 vietnamese (yoyo) loach took 1 month to kill an infestation of over 100 ramshorn snails in my tank ).
Keep in mind most loaches like being kept in groups ...