I am brand new to this. My 4 eight week old chicks are outside full time as of the beginning of this week. They already put themselves to bed at night 
My question is about heat. There seems to be a great number of opinions but I don't know what I should do in my case. The coop is 4x5 and we are in the process of insulating it with 1 inch foam sandwiched between two sides. We only have two sides done. It doesn't seem to be holding much heat at night yet. Hopefully it will be better when we are done insulating it. Last night got down to 54 and it the min temp was 58 in the coop. There is talk of it getting down to 30's soon. Should I heat the coop? Can the 8 weeks old chicks handle the 30 degree nights? I don't know how much heat they put out since they are still young. If I do heat the coop what do you recommend? There is electricity run to the coop and we have installed a light fixture on the roof.
Also, I made a dirt bath mixture of dirt and DE and put it in a shallow bucket. They have already started dust bathing in it. However yesterday they started eating the dirt mixture. They have free choice chick grit and I am sure they get grit off the ground too. Why are they eating the dirt? Will it hurt them? Silly birds.
Oh, what can I give them for entertainment? Their run is 10x12 so hopefully they have enough room but I worry they get bored . I also have a portable playpen to move them about in the yard.
A little info on the chicks. My hubby got them for me from My Pet Chicken. Hopefully they are all girls as he payed for the sexing. There are 2 australorps, 1 buff brahma and one polish crested. There is no chest bumping or anything. They seem to get along really well. The all preen each other. The only thing they do is "square up" sometimes (except the polish). I am assuming they are establishing pecking order. The polish and brahma are so sweet. They like attention and hop in my lap and hunker down for naps. They like to be pet and I can pick them up anytime. The ausies only like attention on their terms, lol. They will hop up in my lap if they feel like it but don't like being handled.
Thank you in advance for any advice!

My question is about heat. There seems to be a great number of opinions but I don't know what I should do in my case. The coop is 4x5 and we are in the process of insulating it with 1 inch foam sandwiched between two sides. We only have two sides done. It doesn't seem to be holding much heat at night yet. Hopefully it will be better when we are done insulating it. Last night got down to 54 and it the min temp was 58 in the coop. There is talk of it getting down to 30's soon. Should I heat the coop? Can the 8 weeks old chicks handle the 30 degree nights? I don't know how much heat they put out since they are still young. If I do heat the coop what do you recommend? There is electricity run to the coop and we have installed a light fixture on the roof.
Also, I made a dirt bath mixture of dirt and DE and put it in a shallow bucket. They have already started dust bathing in it. However yesterday they started eating the dirt mixture. They have free choice chick grit and I am sure they get grit off the ground too. Why are they eating the dirt? Will it hurt them? Silly birds.
Oh, what can I give them for entertainment? Their run is 10x12 so hopefully they have enough room but I worry they get bored . I also have a portable playpen to move them about in the yard.
A little info on the chicks. My hubby got them for me from My Pet Chicken. Hopefully they are all girls as he payed for the sexing. There are 2 australorps, 1 buff brahma and one polish crested. There is no chest bumping or anything. They seem to get along really well. The all preen each other. The only thing they do is "square up" sometimes (except the polish). I am assuming they are establishing pecking order. The polish and brahma are so sweet. They like attention and hop in my lap and hunker down for naps. They like to be pet and I can pick them up anytime. The ausies only like attention on their terms, lol. They will hop up in my lap if they feel like it but don't like being handled.
Thank you in advance for any advice!