Hiya
sorry have only just seen this post, I hope you have been ok with them?
Ducks are very habitual and need a routine when it comes to bedtime.
Do they have a favourite treat?
Try this:
Put them to bed every night just before dusk and keep that regular for them. Try and make it the same person each time and encourage them in with a treat.
It is likely that they have associated bed time with a stressful event, so you are now having problems... they are sensitive little things that dont forget easily! You need to get them to re learn that bedtime = good stuff

Dont worry they will pick it up quite fast, usually within a week or so.
Be patient with them for the first few times. Train them with a specific bowl and start putting goodies in it during the day (try peas or tomatos) let them come to the bowl and investigate. After a while you can hold the bowl for them and let them eat from it, then start using the bowl to entice them in, putting it in the house with some treats in.
It will take a while but they will get into the routine eventually.
Also they HATE being herded with sticks, so dont try that... also any flapping or chasing will just make them even less motivated to go in, gentle hearding froma distance with slow raised arm movements like a wide hug should be ok along with the treats.
Let me know how you get on!!!
zo
x