What are these small insects?

[shalalala]

And what can I do about them?! Thank you

Aphids. They look like woolly apple aphids, but easier to tell if you know what plant they're on (I'm no botanist).

Thank you. They are on a lupin plant

Conveniently called the white lupin aphid!
That was easy to find! :)

Any standard insect spray you can buy at the garden centre should do, or you can use soapy water etc if you fancy a softer option.