De is strip mined, look it up. Not good! And it's a poor insecticide, and bad to inhale. Not worth using, IMO. Sevin (carbaryl) is an insecticide that's no longer approved for use on poultry in the USA. Just don't use it.
Here we use permethrin spray, if possible, or the dust, if it's just...
You aren't going to spray into their faces, and need to wear at least a N95 face mask and long sleeves, and shower after using any product.
Mites and lice will kill chickens; ask me how I know...
And there's no egg withdrawal using those products. Don't wait until your birds are overwhelmed...
Impressive chickens!
Your birds likely do have mites now, and in the USA there's permethrin spray, permethrin dust, or spinosad spray. All work fine, your local feed/ farm store should have the permethrin. In mild weather the spray is least expensive and easiest to use.
That hawk was likely...