I dumped a pack of old mashed potato mix into a flower pot on my balcony and within a minute ants started to haul this mountain of food back to their nest. Since the mashed potato mix is white it was very easy to track where the ants were going.

An hour after dumping the mashed potato mix, I saw at least two streams of ants exiting the flower pot in opposite directions, one heading into the wooden table you see in the video, the other towards the balcony wall. So, there seems to be at last two separate ant nests of the same species living on my balcony.