Swamped

So, half of the duo is nervous about coming to the nesting grounds huh?

You had brought some fly bait to distract the adults. This might work in your favor.

The 'guards are too far for you to chunk the bait at them, but Nina has something that can launch it a little farther.

Pellet the water near the marshguards with some flybait, and wait for the adults to come by and take notice. That will scare the two off.

You can then harvest some eggs to take back to the barge without being detected.

Using nature as your weapon. This is why you joined pest control.

There's a good chance the paranoid one will suspect fowl play, especially if they catch the splash first. If they come back to investigate and see a patch of harvested eggs - they'll be convinced they're right.

But that will take a day or more...hopefully enough time to clear out the greatrats, and get back to operating force.