While searching XGE for interesting passages, I took another look at the spell Infestation to better understand it:
You cause a cloud of mites, fleas, and other parasites to appear momentarily on one creature you can see within range. The target must succeed on a Constitution saving throw, or it takes 1d6 poison damage and moves 5 feet in a random direction if it can move and its speed is at least 5 feet. Roll a d4 for the direction: 1., north; 2, south; 3, east; or 4, west. This movement doesn’t provoke opportunity attacks, and if the direction rolled is blocked, the target doesn't move.
Though I must admit that I see it gives a specific damage an effect, I was wondering what "and other parasites" could mean. Could someone summon a swarm of wasps (the parasitic beetle wasp to be exact) if they also wanted to use the buzzing for their wizard to hide the somatic components of a spell?
Could the swarm of parasites also have other abilities like a swarm (or individual) rot grub?
The target is infested by 1d4 rot grubs. At the start of each of the target's turns, the target takes 1d6 piercing damage per rot grub infesting it. Applying fire to the bite wound before the end of the target's next turn deals 1 fire damage to the target and kills these rot grubs. After this time, these rot grubs are too far under the skin to be burned. If a target infested by rot grubs ends its turn with 0 hit points, it dies as the rot grubs burrow into its heart and kill it. Any effect that cures disease kills all rot grubs infesting the target.
And do they appear and disappear magically or naturally? In other words, is it like you point and suddenly a cloud of parasites gathers from somewhere beyond and then goes back to where they were, allowing someone to capture some of them for material components? or do they not really exist at all?