The spring azure is one of the first butterflies that can be seen in the spring. If you see a small blue butterfly in early spring it is almost certainly a spring azure.
These butterflies can be extremely common. There is a time in the summer when almost all of the small blue butterflies observed will be spring azures. Later, these will be overtaken and replaced by the eastern tailed blue. If you are observing one of these two butterflies from a distance, and are not sure which it is, you can tell by behavior. The spring azure has more of a tendency to fly high into trees than the eastern tailed blue. The eastern tailed blue is found almost exclusively within two or three feet of the ground, while the spring azure can be found at the low level, but is likely to fly high into the trees to escape.
The upper surface of this butterfly is a very beautiful dark blue.
The guidebooks report that the catepillar of this butterfly is tended by ants. I have yet to see this, but I will try to capture this behavior in the future.