I use the MHP in my brooder, so it's dark at night. I slipped my new chicks under the MHP after dark, so they all "woke up" together the next morning like they'd been together all along.
Someone once told me this was the best way to introduce grown chickens. Let's just skip the gory details and say that it isn't. They know. It's just a matter of chicks not being territorial yet. I added the newbie in broad daylight so I could watch their interactions and make sure the new chick had the full tour including how to get water and where the warm is. It really was a non-event.
