I live in south western Ontario, Canada, and I can say with certainty that we have those things all over the place ouside in the summertime.... I always called them "red spider mites" cos I thought that's what they were, guess it's not so simple...
The ones we see here do NOT bite, and in fact don't seem to do much of anything from all I've seen, they DO look a little bit like ticks but they are nowhere near as fast.. they move with a real fluid, steady motion, not erratic..
I really don't know much else about them, since, even though they're everywherre, they never seemed to be bothering anything...
Bugweed's suggestion sounds best, since that would keep them away- they seem to go in cycles up here, one day they'll be all over our picnic table, next day they're all gone and don't return for a long time, if ever....