I'm always well lit at night -- 2 headlamps and 2 blinking tail lights. Few cars to bother me and I haven't been troubled by stray dogs yet. But deer! I always have to keep my eyes out for them. If one runs across the road in front of me another is sure to be close behind, and they're not careful of bikes. Wondering if those ultrasonic whistles I used to see advertised are of any use.