Frontline spray is fipronil, just like the prepackaged vials for dogs/cats- but in a spray dilute form. Fipronil has been heavily implicated in the death/decrease in honey bees & probably native bees. It does work on chickens, but please don't use this if you have any other safer options for the environment. It is VERY long lived in the environment, and if you are spraying this on your birds you are harming the good insects on your property as well as killing the lice on the chicken. Also off label.
Pyrethin/permethrin powder (poultry dust) still works on the majority of the lice and biting mites we see on our birds. It is cheap and does not last long in the environment. There IS some resistance being seen, but again- please don't even consider using fipronil until you have exhausted the on label meds, herbal remedies, ect. For anyone who is reading this---Please don't buy it just because it is easy, and you hear it works well.
If you care about the honey bees and native bees around your county, don't use long lasting insecticides like fipronil AKA frontline. If you have heard about colony collapse disorder - fipronil is thought to be one of the main offenders. Ok, off my soapbox.