When this mod is installed next to the Biochemistry (https://mods.factorio.com/mod/biochemistry), no eggs are spawned from a medium demolisher

Thanks for reporting. I tried enabling both mods together but it seems to be doing what it's supposed to? Small demolisher has no eggs (with or without this mod), medium and big ones have eggs (with or without this mod). Might be some other mod doing it. Could also be that the medium demolisher head (which has the eggs) got marked for deconstruction and a bot picked it up before you mined it. Biochmestry mod adds a new boulder type for the demolisher's head that is supposed to hold the egg