Karen,
we took our kids to the Weiser, Idaho old time fiddle festival one year and took their bikes along so they'd have something to do. As we were setting up camp, we gave the kids their bikes and said, go have fun. They were both back in 5 minutes with flat tires. After several more flat tire incidents my husband eventually bought tire liners and flat tube foam (I forget the name of it). My sons also got better at avoiding the goathead weeds.
They are fairly easy to see once you get to know them (ouch, I have) they are very low to the ground and kind of lacy in their habit.
They don't seem to like the cool climate here thank goodness