I hate you people ������
Now I can’t get that song out of my head!!!
Hope the kitty gets better.
I’ve found cinnamon to be very effective against ants. It completely destroys their ability to detect the pheromones they use to lay trails.
When I had a problem with ants, I put cinnamon in the tray the cat food was on, and made a little pad of cinnamon sticks that the food tray went on. Then I put a line of cinnamon on the threshold of the door where the ants were coming in.
Googling shows that cats can have a problem if they inhale the cinnamon, so maybe just the cinnamon stick pad, and try to find where they are coming in so you can put cinnamon there.
Thanks for reading my mind and making feel just a little less like an oddball.
Plate on top a metal mixing bowl with a deep overturned rim works nicely. The requirement to walk upside-down to get near the food seems to deter the nasty little insects. As a bonus, if your kitty doesn’t like bumping his whiskers on the bowl, he’ll find it easier to eat from the plate.
Cayenne pepper is supposed to deter ants, but also cats. However, you might try pouring into any crevices the ants might be using to come inside. If you’re not sure where they’re coming from, leave out a piece of food directly on the floor and there will be a steady trail of ants to guide you.
And yet another Terro fan, I had the same problem and it worked great.
Extra protein for your furbaby, whether you think of the cat that way or not!
Anyway, since YOU don’t want ants, I’ll tell you what I do when they invade. I wash the dishes and underpad, and the floor, and relocate the dish. They’ll figure out where it is. 
I then spray the affected area, and also put Terro traps in places where the cats can’t get to them.
I’ll note that when we had ants in the house, coming from behind the cupboard, the Terro worked in about 1.5 days. Research on the internet said that these were Argentine ants.
When we had an outdoor ant nest, though, it took about a week for the Terro to completely eliminate the colony. But these outdoor ants were of a different species - they were bigger and blacker than the Argentine ants. We replaced the bait about every other day, and they kept enthusiastically drinking the whole time. Finally, the outdoor colony just vanished.
Food grade diatomaceous earth might help.
We get ants pretty bad in the summer time, and no store bought trap/bait/poison made a dent in them. We ended up calling a pest control company that comes and sprays around our house. That keeps em out/dead for the whole summer. They are still around outside, but they must find somewhere else to get food.
It costs about $150 to do this once, but we only have to do it once a year. More expensive than other solutions, but it actually works.
Terro plus put the cat food dish in a saucer of water.