Where's Waldo? Try artellius waldotis, they are a more photogenic ant, plus they're easier to find than standard ants (due to their red and white stripes and the fact that they leave backpacks, canteens, and cameras, whenever they travel)
To busy the ant is lost. Take a quick look at the picture notice where your eyes focus. From the definition minimalism I would say the brown leaf in the right or the brown spot just down from the top would be the minimalism focus point.
I think the point of the challenge was to have something small that stood out, and you didn't really have to search for. (At least that was my understanding). A simple background (white paper even) with the ant would have worked much better for me.
You're right, you have to look for it, but the point of the challenge was to have something small that was the strong point of the image. . .if you have to search it isn't really the focus of the shot.