The Desert View Watchtower was the first sight encountered once inside the park. At the park entrance gate, everyone was greeted by billions of little gnat-like bugs that crawled all over your car and made our day trip to the park somewhat like an Alfred Hitchcock  movie.   Apparently they hatch and take over the entire park for a few days every spring.  Lucky us to have arrived on their first day. They swarmed everyone throughout the entire Grand Canyon South Rim at every overlook.  When we'd get out at the vistas to take pictures, hundreds of them would land on you and even though they didn't bite, they freaked everyone out by the sheer volume of them.  We'd run in circles around the car brushing them off, do a quick open of the door, jump in and slam the door as fast as we could, then spend the next 10 minutes crushing those that got in against the inside windows. I took the rental car to the car wash the next day and spent $2 in quarters vacuuming out all the dead gnat carcasses.