Pennyroyal is a ground-cover herb that grows like a weed. Ants can't stand the stuff. We found that putting a few sprigs in the bottom of a pot before adding the dirt does wonders to keep the ants from making a home in the potted plants. It pulls up with roots easily so we transplant it right over the ant hills. Man that pisses them off, but they move on. It's also a great insect repellant for your body - just crush a few leaves and rub them over your exposed areas.
As for the spiders, the tiniest ones need something to eat and aphids sound about right. We have a no-kill rule for spiders. There are very few you need to worry about getting bitten by and they do far more good than any possible harm. Lady bugs are cute, but they're indiscriminate consumers and while they do munch on aphids they also eat beneficial insects. Don't bother buying them. They rarely stay in the spot they are released. Praying mantis is another "eat everything in sight", but on balance both lady bugs and praying mantis are beneficial. I read somewhere that a praying mantis male can't achieve while his head is still attached. Sounds about right.