It depends on the drake and the size of the pen or area where they're kept. If there's plenty of room, mama will usually watch over and defend them and the drake will mostly ignore them. But, some drakes are duckling killers, so it's best to keep an eye on them. I've seen where drakes will be fine with young ducklings, but when the ducklings get older and start to feather out, the drake will begin nipping and chasing the ducklings. And, vice versa, some drakes attack small ducklings but ignore the larger ones.