well, since you ask, I have an annoying thing going on on my balcony: ants making a home in a planter. I bought a hellebore the other week, and haven't had a good container to put it into, so I'd been keeping it in a slightly protected spot by the wall of the building. The nursery pot seemed decent size, so I didn't think it would be a problem. But then I noticed that the plant was deteriorating really quickly--first the blossoms, then various branches. Yesterday I finally decided to transplant it. When I unpotted it, I noticed a big lack of soil on the BOTTOM of the planter--weird. Then I noticed an abnormal number of ants. Tons, swarming. A little research showed that ants can indeed nest in a planter. Yuck. I'm taking the advice I found online and am flooding the planter & soaking it in a pot of water overnight. Fingers crossed that I killed the colony. That was an expensive plant!

Wow, what a nuisance. I've had gnats galore and I put strips of sticky tape along the rim of the pot. Pretty soon the tape looked like somebody had prayed it with pepper. The gnats didn't fly onto it, it's when they crawled around the rim that they got stuck. This helped for a while, then I had to do the whole thing again. I wonder if this would work for ants as well?

I may also be experiencing gnats, some sort of very small wingèd creatures, all over the place. Do they do any harm? or just look ugly?

They lay eggs in the soil and the larvae may stunt or kill your plants when they feed on the roots. Someone mentioned that they need moisture, so you may want to hold back with the watering a bit.
Ingrid

Many of my plants are tropical and need moisture so I add some vermiculite so the soil drains faster and the soil fungus the gnats feed on does not grow and the gnats stop reproducing. This also helps the root system grow faster and stronger.

I have one planter I was keeping in a greenhouse for a bit, which seems to have allowed it to grow some fungus in the soil, and have a happy colony of gnats now. I'm hoping I don't lose the peas, beans, and carrots in there - no idea what's going on under the soil. :(

We have a crappy weather forecast showing 10 days of fog/rain/cold coming up, doesn't bode well for this gnat situation.