It is very hard to determine from the picture but it resembles a Fungus gnat larvae which is white/translucent with a black head.
try placing a yellow pest sticker in your grow space to easily identify the pests!
There are plenty of organic ways to deal with pests such as natural predators (like ladybugs mentioned by
@HarbingerOfHarvests), or organic oils and extracts (such as neem oil, and tomato leaf extract) to mend pest problems!.
*there are plenty of organic pesticide recipes online but most don't mention tomato leaf water/extract.
Hope this helps! Good luck and happy growing :)