Scott, it's much better to use a bait rather than spraying for ants. Bait will get the whole colony and kill the queen. Try the Terro liquid bait stations, and if they won't take that try Amdro granular bait.
Spraying will just kill workers and more will hatch. Plus it also will cause the ants to make new nests.
If you're thinking that the ants are hurting the plant, they probably aren't but as Tiffany says you should definitely check to see if something else is going on. Once you've cleared out enough ants to see the area on the palm, a horticultural oil spray may be the next step to kill of the scale insects so the ants don't come back.
