All of my flocks and penned birds roost where mosquitos can and do get to them. The birds get but a lot. On all but coolest nights it is easy to see at least a few mosquitos with abdomens distended with blood hanging near a chicken. Sometimes a couple hundred mosquitos are evident. This year has been exceptionally wet so controlling mosquito numbers not practical. Birds roost in predator resistant coops, elevated roosts and birds of particular interest roost on front porch. Front porch birds includes two broods of bitties, each tended by a hen. Birds not enclosed in large part owing to concerns about ventillation on hot nights. It would be difficult to physically obstruct mosquitos anyway as they can get through some really small cracks. I am working on a repellent system but so far not found anything practical. The chicks in particular appear to be having a difficult time. Disease transmission a risk and likely occuring but actuall reduction in vitallity of chicks may be related to actual high volume of blood loss. Anyone know of any feed additives or supplements that can promote increased blood production?