They will when they get used to the fact that the light is gone. If they are using the pad at night, they definitely know where "warm" is, but chickens (and their little counterparts) are creatures of habit. To them the lamp during the day is their "normal" and if it's not there they get confused, - and the owners panic. If I'm visualizing what you're saying, you turn the lamp off and then stand there to see what they'll do, is that right? So they suddenly have no light, no warmth all over the entire brooder, and you. Yep, they'll be confused. They aren't huddling as much for warmth as they are for security. So turn it off. Tuck a couple under MHP and hold your hand gently in front of the opening so they can't get back out. This just reminds them of where the heat is. Put some treats in the bottom of the brooder near the opening of MHP, or even on top. Then walk away. Leave. Let them figure it out. Come back in an hour or two and just peek in. You might be very surprised.
I don't have any scientific expertise to back up my theory, but I believe that by doing absolutely everything for the animals we care for, we do them a huge disservice. They don't have to rely on their own brains to help them figure out what to do. Ever heard someone talk about a dog that is perfectly capable physically of jumping into the car, but won't do it because he never had to learn? From the time he really had to be picked up and put in as a young puppy, physically unable to do it yet, the work was done for him. As he got bigger he just stood by the side of the car while the owners tried to coax him to do it himself, but he just stood there, waiting for what he's accustomed to. And they picked him up an put him in, again and again. Now 5 years later here he is, 60 pounds of dead weight being heaved into the car while the owners complain. Yeah, it's like that. We all seem to be of the mindset that says we have to do everything for our chicks - we don't. Instead of them being little divas, we need to let them be chickens. One of the things they need to learn to do is how to meet some of their own needs. We do need to provide them with an adequate diet, plenty of water, and a safe and clean environment. Providing some things for themselves - scratching in the ground and finding little bugs and such, self regulating their heat needs and exploring to learn their world - is just what Mom would do. Good luck!!