I found and eliminated 3 of those munching on my 10 day old seedling, who are they and where could they come from, will there be more and are they dangerous?
Tiny baby caterpillar.
Good thing you caught them early.
Watch out for butterflies and moths around your plant.
You can give it something with BTk in it.
The bacteria form a relationship with the plant and help keep most of the caterpillars from eating your plant.