I have two lovebirds they laid 4 eggs one of the lovebirds is eating
the top of the nestbox i do not no why .i am scared that the top
will fall off and smash the eggs cuz i want the eggs to be fertil.
and if the top falls off the eggs wont have darkness.

one thing to do is change the nest box. make sure not to move the eggs to much. but if there is a change the top may fall down. its best to do so. the bird might also be getting nesting material from the box. my female always dug up some of the wood from the box to put in the nest. as well the eggs don't need light or dark they only need warmth at this point.

Peach face Lovebird breeder

Birds like to keep there beak sharp, other wize they can grow really long. This might me the problem so provide them with cuttlefish to chew. Some of my birds still chewed the nesting boxes even though they had cuttle fish. If this is your birds first lot of eggs, it's best not to disturbe them at all. I would leave them but provide another nesting box and hope the lovebird doing the chewing picks on that box instead. Hope I helped.