Two of my chickens are standing still, puffed up and are closing their eyes

I found some red ones and I don't know if these pictures are good enough

OK. Red mites normally live in the coop and feast on the birds while they roost. They are a real pain in the neck and diatomaceous earth won't get rid of them (though it may help with preventing reinfection after you've got rid of them). There are various products for sale that claim to treat red mite infestations. This website has some useful guidance
https://www.chickenvet.co.uk/red-mites

Amy-Joy said:

My father is the one who cleans the coop and he's not home right now so I can't ask him. I don't think we've ever medicated them (and I don't know if they ever have been medicated before we got them). We had given them diatomaceous earth a few weeks back because we had seen some type of flees but since then, we didn't see some on them (saw a bit of them around the coop but on the outside) My father put some diatomaceous earth in the coop this morning just in case.

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It looks like you are feeding your chickens scratch. Scratch is not a specially formulated chicken food. It is a treat that should be given sparingly. Change this as soon as possible. Scratch contains corn which can cause a condition called crop bound. Check her crop early in the morning, if it feels hard and full, this may be the problem.

InterestingChickens said:

It looks like you are feeding your chickens scratch. Scratch is not a specially formulated chicken food. It is a treat that should be given sparingly. Change this as soon as possible. Scratch contains corn which can cause a condition called crop bound. Check her crop early in the morning, if it feels hard and full, this may be the problem.

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Apparently, the food came from the breeder where we got them and wasn't supposed to be used as treats (at least that's what my mother told me) but I've had a look at the packaging and there is indeed some corn in it.

Amy-Joy said:

Apparently, the food came from the breeder where we got them and wasn't supposed to be used as treats (at least that's what my mother told me) but I've had a look at the packaging and there is indeed some corn in it.

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Don't worry; for a lot of users of BYC, commercial feed is the only acceptable feed. Their views are based on US history and traditions, involving a lot of corn (aka maize), whereas UK traditional feed is wheat based. The main difference is that, because it's homogenized (and usually pelleted), you have no real idea what feed manufacturers have put into their feed (recently shown to include plastic in the pig and cattle feed industry). Personally I prefer to feed my chickens something recognizably food. You might find this useful too https://www.backyardchickens.com/articles/primal-chickens-–-6-chicken-keeping-secrets-from-the-evolution-of-chickens.73654/ especially 'Diet', about half way through this long article.

InterestingChickens said:

Scratch contains corn which can cause a condition called crop bound.

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would you care to cite some evidence for this statement? Otherwise it will look like you are scare-mongering.

how are your girls @Amy-Joy ? Did you manage to get the coop cleaned? Find more red mites?

Perris said:

would you care to cite some evidence for this statement? Otherwise it will look like you are scare-mongering.

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The resoning behind this is too much dried feed can cause an impacted crop. I do recall @Wyorp Rock mentioning this a number of times. Please correct me if I am wrong. Thank you.

Amy-Joy said:

More information : my other 3 chickens are just fine. My father put some diatomaceous earth on them just in case it was mites. The two chickens drank a bit and ate the cheese I tried to give them (the blue one wouldn't take her food) The red one seems in a better shape, she walked a bit and ate more. But the blue one juste keep 'falling asleep' and she now is closer to laying than standing. It was hot yesterday (around 25-30°C) I don't know what to do, I need help please.

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Have they experinced natural heat like that before? It could be heat exhaustion. Give them lots of water and electrolytes.

InterestingChickens said:

The resoning behind this is too much dried feed can cause an impacted crop. I do recall @Wyorp Rock mentioning this a number of times. Please correct me if I am wrong. Thank you.

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I have not seen scratch in general and corn in particular cited as a cause of crop binding, but perhaps Wyorp Rock will come along to clarify.