They can I had a Muscovy hatch her egg taking 3 days until she finally gave up and left the nest with her ducklings the last one died in the shell. Be sure to put feed and water[a safe waterer] close by mama and ducklings so they can eat and drink while mom is still sitting. Mama can eat starter...
when you look at the egg can you see where the duckling is working on the shell that is called external pipping the first internal pip where they chew through the membrane next they start chipping away at the shell all of this can take up to 36-48 hrs ducklings take their sweet time hatching.