Interesting about the Vit. B. Will have to try that one!
I am sure the DEET works really great, but since we don't like to use harsh chemicals on our skin (esp. on our children), we have had great success using Avon's Skin So Soft Bug Guard Plus. It comes in handy individually wrapped wipes, ( in addition to tubes and sprays), which are so convenient for travel. It's supposed to work for up to 8 hours too, but we have only applied it in the evenings, and it has worked out great for us so far!