I just imagined small trees emerging from that pot and wondered how those'd look like?

There are some grubs to be found each year in some of pots on the balcony. I collect them and move them to a large compost in a nearby community garden later. Until then they can rest a moment in the temporary grub pot. They're not so cool to have in pots, since they can damage plants if they run out of plant matter.

But they're great to have around otherwise. Nice snacks for local wildlife (birds and hedgehogs), great for soil health as they are diggers (like slugs and other soil macroarthropods), and they help decomposting and improving soil quality with their poop.

@rra