Did you know that the Yolo Wildlife Preserve is home to one of the largest colonies of Mexican free-tailed bats? The first time I saw these guys, I was on the way back from the Bay Area and stuck in traffic on the causeway. The sun was setting, and suddenly, a stream of these bats comes up from below. At first I thought they were birds, but then I noticed the strangeness of their flight patterns. I looked it up, and sure enough, we have a colony of 250,000 hiding in plain sight. Amazing!

So, of course, I had to get a closer look. A few days later, I looked up the time of sunset, and arrived a few minutes prior. We parked next to the causeway, on the gravel trail, then walked right underneath to wait. As we heard the high pitched echolocation mounting in excitement, we began to see a few lone bats dart out to check out the situation. Once the timing was right, they began to swirl around beneath the causeway, before streaming out in a ribbon across the cotton candy sky. We watched until they disappeared into the darkness, presumably in search of their next meal. 

Since then, we've come to watch them begin their nightly hunt every summer. 

If you are inclined to be a little creeped out by these guys, keep in mind that they eat insects. I'd say they are friends! And if you want to see this spectacle for yourself, go soon! When the weather cools, they will migrate south, and you'll have to wait till next year.