Hi, I take it the photo of the first bugs in the bag are different to the one in the next few photos? the ones in the bag just look like chicken lice to me, a very common parasite that are just leaving the hosts feathers as she has died, kind of like rats jumping ship! they need to find another living host or they too will die, I would not be overly worried about these they are unlikely to have caused your pullets death, they are hard to see otherwise but most birds have them to varying degrees. The other photos with the maggot like bug I'm not sure about, what is the actual size of it? it looks as if the photo has been blown up to show detail, if this creature was found amongst the chicken dirt I would assume it lives within the dirt in the run and again is harmless, I am sure years ago when I had pigeons breeding on my balcony these little critters were found within the nest material eating old feathers and the like and did not directly harm the birds, mealworms are completely harmless and are not related to these, they have a stage in their life cycle where they look remotely like them during the pupal stage but that's all! mealworms do not predate chickens!!!!
