Excessive scratching...

[Possum-Pie]

We got 4 new hens 2 months ago. One was a bit raggedy but I saw no infestations. I had no real way to isolate them at the time so put them in with our original 3. The raggedy SLW looked like she was finishing a molt, but I began noticing that she "preened" more than the others. Couldn't tell if this was digging at herself with her beak b/c of bugs or something else. Anyway, the rest of the chickens (to a lesser extent) have begun scratching more, so I examined them all carefully around the vents, under the wings, and necks but saw no mites, fleas, lice, etc. I treated the whole flock today (and the coop) with Diatom. Earth with a small bit of Sevin mixed in. It has to be bugs, but the temps are in the 20's around here and bugs usually are more common in summer. Does anyone know what type of infestation would be so small that they were unnoticeable?

SLW tail...notice the shafts are intact but the vanes are torn and missing. She is low hen in pecking order and I was concerned that another hen was pulling on her tail feathers but I've not seen it.

 

[Possum-Pie]

No suggestions?

 

[aart]

Might be feather mites, which are virtually invisible to the naked eye, or you're just not seeing the bugs, you have to look down at skin level and be fast before they run off and hide.
Wouldn't hurt to give them a dose of permethrin spray on their skin in the areas you mention and see if it helps.

 

[Possum-Pie]

Thank you for your response aart. It very well could be small parasites...they scratch their skin like I've never seen. I dosed with Diatom. Earth and Sevin powder mix. I'm looking at the "coop cam" as it is snowing and they are all in the coop. A few are still digging at their wing/backs but much less than 2 days ago. I will re-treat in a few days to catch eggs, but this may be the solution. I just worry b/c my EE and SLW are always picked on. I'd cull any hen that injured them but I only see bullying behavior so far...