Before they get to your place, go to the store and buy yourself one of those kid-resistant doorknob covers, a door closer that attaches on the door hinge and a spring loaded hook & eye set. (this is the set where the hook has a spring loaded cover that must be pulled back to un-hook it. Very child resistant. Even some adults resistant) and one or 2 child safety gates.
Install the door closer in one of the hinge pins. You can do it, easy. Adjust it to close the door tightly.
Install the spring-loaded hook & eye up high on the door jamb where the kids will have to get a chair to get to it and an adult will have to look up to undo it. fasten the hook. practice undoing it so you are able to open the door quickly.
Add the child resistant doorknob cover to the doorknob facing out of the room. This won't stop anyone, but it may slow them down.
(Or knit or make a fabric doorknob cover out of a circle of fabric large enough to completely cover the doorknob all the way to the door. If you make it big enough to cover the shank of the door knob, you can put tape over the fabric that covers the shank so the cover cannot slip off the doorknob "accidentally". Just be careful that the tape doesn't stick to any part of the doorknob or shank. You want it to slip and slide when the kids try to open the door.)
Once they arrive, sit down with the entire group and have a friendly rules session. Make sure everyone understands and follows the rules:
We have baby ducks. For their safety, we have these rules.
1) Only adults are allowed to open the duck room door
2) No dogs in the duck room
3) No ducks out of the duck room
4) Duck room door must be pulled shut every time. You must hear the click of the latch.
5) Anyone not co-operating with these rules will not be allowed duck time.
Post the rules on the duck room door.
Kids who want duck time will co-operate.
Finally, depending on how well the dogs can jump, put up the child safety gates in the door jamb outside the door anyway to keep them out and slow down the kids. If the dogs can't jump, you may only need one and can step over to go in the duck room. If they can jump, you will need 2 gates - the higher one will need to be taken down and put up whenever someone goes into the room to keep the dogs out.
Or, put leashes on the dogs and tie them up, or segregate them in another room.
Yes, this is a lot of work. But it is worth it if you want to protect your ducklings.
We have kids, cats, dogs ducks and chickens and eggs in the incubator. Those eggs are locked up tighter than Fort Knox because of our grandchildren's 'helpfulness'. At ages 5 and 3 they want to turn eggs, adjust the incubator, give physical therapy to an injured hen, and generally help with anything to do with the animals. Unfortunately, they have very short attention spans and small, cute, less than skillful hands. So they are carefully supervised when they want to see or hold the cuteness.
Hope the visit goes well and everyone has a good time!
ETA: If you think you can reach them before they leave, go ahead and ask them to leave their dogs at home. It is your house, after all. Or do you have some dog crates you could put the dogs in when they are not being supervised? To cut down on the mayhem?
The door to the room that they are kept in will be closed 24/7 while they are here, but the door doesn't always latch securely. It's not a big deal at all-you just give it a little tug-but my cousins won't remember to. I'm going to make a rule that no one goes in without me, but I'm fairly certain that that the cousins are going to try to sneak in anyways at least once. I don't mind much because I don't think they would try to take them out of the pen (But what if they do?! The duckling will run from them and the cousins would chase them and be all rough....
