My chickens are Defective

Finally took the plunge and got 4 chickens and 4 ducks from TSC about 2 months ago.  One chick was sickly/injured and didn't make it out of the brooder and had to be put out of its misery.  The rest all thrived and are living outside together in more or less harmony.  Which is to say my chickens think they are ducks and my ducks think they may be chickens.  In spite of everything I had read on them my ducks are the ones who put themselves to bed at night while I have to herd the chickens in.  Of course the ducks spend most of the day in their house so that might be part of it.  Neither the chickens or the ducks like to forage very far from the house at all.  If the ducks do decide it is time to forage the chickens follow.  If the ducks go for a swim the chickens forage around the area the pool is set up but return to the house when the ducks do.  Unless it is night time and they should be going to sleep-then they run around the yard like toddlers at bed time .  I am so disappointed in my chickens that I went ahead and purchased another 5 chicks from a local feed store :p  

All joking aside raising birds has gone much better than I thought.  No issues with health outside of the one who was sick when we bought her.  With two dogs who roam the yard at random intervals day and night and backing up to a fairly busy road we haven't had any issues with predators yet.  My smaller dog is an active hunter and killed a rat at night a week before the birds went out and haven't seen any signs of rodents since.  And despite it not seeming like the chickens are doing much in the way of foraging they rarely eat much of the feed and even the ducks don't eat as much now as they did when I first put them outside so they are getting food from something else.

The biggest lesson I have learned so far is not to raise duckling and chicks together-the ducklings are entirely too messy!  That and the fact that my neighbors don't mind the ducks and actually like the sound of a rooster so are cool if I get one if I share some eggs with them

That's odd about your chickens not going to bed. Usually that's a super strong instinct! Mine go to bed early to stake out the best roost positions. Every once and a while somebody will miss the auto-door.
It's an adventure for sure, and there are a million different ways to raise your birds. I though I was safe from predators until last fall about this time I lost 2 young birds to hawks. So if you see hawks migrating through, consider scarecrows.

Is there a light inside the coop? That might encourage the chickens to go in at night. Also, make sure that the roosts inside the coop are the highest ones available to them. They seem to like high places.

Roosts are off the ground highest point available.  They go to roost eventually after I put them in.  The ducks on the other hand go to bed on their own.  To be fair the ducks seem to prefer to stay in the house unless bathing or feeding though