Honestly, we own and run 3 townhomes, and we've never had ants in any of them. I have been in dozens and dozens of townhomes, and never seen ants in any of them. It is Florida though, ANY property can get bugs or ants, it's Florida! The land of bugs and critters! What's important, is that the home has regular pest control (EVERYONE in FL has this!)...and they have a good MC in case you have any issues or problems during your visit. Everyone has small issues from time-time...you have them at home ...right? It's what you do about it that counts...and it will be the MC taking care of any issues that may come up! This is true if you irregardless of if you stay in a hotel, condo, townhome, or pool home!
As you say anywhere can get ants but most owners pay for a pest control expert to get rid of them. We pay $25 per month to our Management Company and would be annoyed if we ever found an ants problem at our villa.