Found dead with mucus around eyes and beak?

[chookchooks123]

Found my 6 week old chick dead with green mucus around its eyes and beak today. Prior to this, she seemed fine and nothing out of the ordinary.
The body had little white bugs crawling all over it, and i noticed a couple of the same bugs under the feathers of another hen. Only a couple though.
They all seem fine however
Is this bird mites? Or something else?

 

[azygous]

I suggest you take this dead bird to an animal testing lab for a necropsy. It's the only way you can find out what killed it. If you provide your location, we can help you with that info.

This could be a simple respiratory illness or something much more serious, and it's likely the latter since it came on so suddenly. Avian flu comes to mind. Again, if you would provide your location, we can help with this info.

There is a chance she got into some rat poison or some sort of petroleum distillate such as insecticide or automotive fluid. Do you have any old cars leaking fluids onto the ground where the chickens range?