Ants: Follow their path (which is sort of obvious by their coming and going) and put down boric acid around the entry way. That will knock them out in about two weeks.
Fruit Flies - use an empty soda can or bottle and fill it about 1/4 full of vinegar with a little fruit juice. Also put up pull-out fly paper hanging traps. Between the two, you'll be good in about a week. They breed VERY quickly (like a day or two for a brood). Get that going immediately
If you put the worms outside, they'll probably die. It's too late in the season to put them out even in an open-bottom container. You have to do that by the end of October so they have time to burrow down for the winter. Under the sink is the best way to raise them.
Don't worry about cats - they aren't interested unless the things are crawling on the floor. They'll kill them, but won't eat them. If you DO have cats, keep the boric acid out of their reach. It won't hurt them in the long run, but it will make them bloated, cough up hair balls, and probably get the screaming shits.