Our Shelduck Jeff and our 2 Khaki Campbells love earthworms, here in NZ in rural areas like where I live, the most common size is about 5 - 7 inches long and about 1/2 an inch thick, very hard to find small ones out here, all three of the ducks do a hilarious happy dance when it's treat (worm) time although Jeff ran away from the first big worm he saw, but like most small children couldn't resist coming back cautiously and tasting it then it was all go after that, it does make gardening interesting having 2 ducks and 3 chickens leaping into any hole you dig looking for worms and if I go to get compost from the heap there is always an appreciative audience in tow! 😁
Let him mate your khaki girls!!!!! I wanna see the mixes!!!!!