Looks like aphids to me.

DM

I'd agree, does look like aphids. But the photo isn't very clear.

Here's a little closer.

yep, aphids

Are these just regular aphids or a specific kind to mangoes? I've never had them and now with a few mango seedlings they arrive lol. I hate pests!

They look the "regular" type. Ants can bring them around. But if yours are indoors then most likely came off other plants. Should be easy to control manually, between the fingers. Just keep checking for any new hatchings.

Ok. They are outside but I've only found one other mango seedling with some on it. I'm getting worried because I have a ton of Seville and sweet oranges and I know aphids transmit tristeza! Thanks for reply.