But I haven't seen a single dud egg since

Oh, they don't lay many dud eggs, but I did have one short period of time where 3 were together up to a wall and they laid like 20 dud eggs

i keep hearing that scaph increases the chance of dud eggs, but my dogs lay functional ones. how many dud eggs does your dogs in that group lay?

oh yeah i have a room which is just en ecosystem where the only sources of food are flora that cause random mutations. Half-chewed food, poop, dog corpse parts, cocoons, etc. A dog is born, it eats dog corpse parts as its food source, it poops, and might half-chew some food, from the corpse parts, creating more food to hold it and the other dogs over until the next pupation or death, and cocoons are the second food source. Since you gain a net loss in the amount of poop and chewed, corpse parts and cocoons end up being the main food source, which is about enough to sustain them along with the poop.