Tourists won’t be the only thing hogging the Big Apple sidewalks this summer. When people think of New York City rats, they usually picture woodchuck-size vermin darting through alleyways, or bursting through basement ceilings a la “Ratatouille.” They’re not wrong. During a recent ride-along with veteran exterminator Favio Ulloa, The Post didn’t spot a single rodent —we must’ve gotten lucky. But our lack of sightings wasn’t evidence that they weren’t there.