I agree with 1duckychick. Mine act the same way. Just up to about a week ago, they would actually be waiting inside their pen at sundown, but this last week I had to herd them in. A friend gave me a mallard and he's trying to lead my Pekins astray. When they were little I use to catch a few flies for them in he barn and give it to them when I put them in their pen, but I since they started free ranging during the day I no longer give them or my chickens feed at night. "minifarmer" mentioned using hog panels to guide his ducks in. I use to use a half open gate to guide my geese into their pen at night but they would get to the gate and stop looking confused. I'm not sure what they see? I took away my "guide" and they go right in:/