They are very small and look like the earliest stages of thrip larva, but I have never seen an adult thrip, even though I see these guys often, so I don't think that's what they are. They walk on legs and have antennas. I find them in the bottom of tropical plant pots inside, and also in the bottom of veggie pots on the balcony in the summer. They do harm the plants where they live (slow unhealthy growth).
Edited to add more details:
The biggest ones are only 2mm long, which is why it's so hard to get a good picture. They start much smaller, and there can be hundreds of tiny dots/threads in the bits of liquid in the tray under the pot. They have 6 legs, and can jump when trying to avoid a stream of water. They are slightly off-white compared to a pure white piece of paper. They are somewhat bulbous like thrip larva, and they can be a bit transparent.
What are they, and how should I get rid of them?