It is rare that we get to see the flowers of Liriodendron tulipifera while they are fresh. The tulip poplar is a tall, straight tree and the flowers are usually well out of our reach. However, Hurricane Isabel blew through in 2003 and dropped quite a few trees without killing them so now we get to see what is normally in the canopy rather than the understory.
The ant in the picture is after the nectar produced by the flower and exuded along the orange surfaces. It is a sweet treat and we can be seen taking a taste now and then when we are lucky enough to find a fresh flower.
You can see the nectar if you look closely at the orange part of the flower above. It tastes like honey. Of course, I recommend inspecting the flower before tasting the nectar -- unless, of course, you don't mind eating an ant or two. :)