I know I say this alot but I feel it's best for mama and ducklings to have time to them selves. where the rest of the flock can't get to them, where they can all be seen to get use to each other but where the mama and duckling can just have time to bond and ducklings can get their legs under them good and grow a bit before having to deal with the other adults. I use the plastic poultry fencing from Lowes to cover any fencing with too big of hole so ducklings /chicks can't get caught. much cheaper than hardware cloth too. But if you don't lock your flock in secure housing at night and they stay in a run I'd go with hardware cloth. Sorry about your losses.