I enjoy trying to get good close ups of ants, mainly because they are so tiny and always moving so its quite a challenge. I use a few different methods. One would be to follow along slowly trying to get shots hoping something might be sharp.
Nikon D750 1/320 sec. f/9 ISO-160 at 35mm
The other method is to try and pick a spot where I think the ant might end up and wait, worked pretty good fro this flower as the any stopped for a moment to probe the flower with its antennae.
Nikon D750 1/320 sec. f/9 ISO-160 at 35mm
Nikon D750 1/500 sec. f/9 ISO-160 at 35mm