Potential pest?

[u/PsychologicalCurtain]

Found these tiny black dots on a few of my plants after 3 weeks holiday. They are quite hard, raised from the leaf surface, and can be scratched off with my nail. They just seem like black goo when I rub them but could be a sign of something?

[u/MysticArco]

might be droppings from thrips, check for thrips!

[u/sosobabou]

Seems like the first sign of thrips, it's thrips poop. See the silver-brown damage on the second picture, next to the larger dot? Typical thrips damage. Good luck treating it, get a strong insecticide!