[SusieB]

If I quarantine my new ex-batts, and they meet my current hens at the fence.  Can the red mites hop over?  How far apart would I need to keep them?  Does any body know the long jumping skills of a red mite?

[GrannieAnnie]

I've never seen them jump.  I don't think they can.  They usually crawl up into little cracks and crannies all over the coop, dropping onto the hens at night to feed.

They don't usually live on the hens during the day, but some can accidentally get a free ride, then they drop off and crawl to other places.

You only need 2 though and within the week that they live, they can have millions of babies.

[Sassy]

Whilst quaranting best for them not to meet your chooks even thro a fence 

[8doubles]

Do not forget that wild birds can also carry mites and drop them near the coop.
Some birds nests are crawling with mites and ticks and other nasties.