I fear, from past experiences, there is no effective prevention of bites from these little bu&&ers. My wife reacts badly to mozzie and midge bites so we avoid Western Scotland during the sumner months. A very effective form of midge killer for inside the van was a plug in one that our son in law used in, and brought back from India. Goodness knows what the chemical was in it but in the morning it looked like we had spilt a bag of tea leaves in the van with the amount it had killed.