The main function of the bird bath in our backyard is to provide water for the neighborhood birds. But birds are not the only animals that utilize the bath. I have already written about the very abundant bdelloid rotifers that live in the water. The other nite I witnessed another group of animals apparently partaking of the water that was being offered. They were isopods.
In this and the next photo the red dotted lines mark the approximate position of the top of the water.
What were the isopods doing in the bird bath? It had rained earlier and at that time (this was around 2130 hours) the ground, the grass and all the other plants were wet. If the isopods needed water, they certainly didn't need to climb all the way up to the bath, which is 60-70 cm above the ground. Moreover, how did they know that there was water up there?
Terrestrial isopods evolved from marine ancestors (more on isopod evolution here). So I thought maybe they were reenacting the emerging of their aquatic ancestors out of the sea onto the dry land millions of years ago. But later when I saw the next picture, I changed my mind. I think they just like to look at their own reflections in the water.