Ok but where do they lay them?

Bro, you haven’t lived until you’ve had deer egg omelettes.

Deer don’t have refrigerators, of course they’re going to ask where to keep eggs. You don’t want your eggs spoiling before you can use them.

Obviously this is for North American deer, European deer have access to fresher eggs that don’t need refrigeration.

Maybe since ‘deer’ is already plural, it assumed you were interested in deer flies.

They lay “their eggs in masses on vertical surfaces like leaves, sticks, or rocks that overhang water or moist soil, with a shiny coating for protection, so the larvae drop into the wet environment below to develop.”