You tried all the natural methods. You may have to go nuclear.
On a nice day, have someone take the ducks to the park and use "flying insect spray" all over their room. Leave it sealed up for a couple of hours and then air it out before letting the ducks back in. It should take care of them in one or two treatments.
On a nice day, have someone take the ducks to the park and use "flying insect spray" all over their room. Leave it sealed up for a couple of hours and then air it out before letting the ducks back in. It should take care of them in one or two treatments.
