Hard to say without knowing what insects they are. Are they on the flowers or the stems and foliage? Open-faced daisy-like flowers attract a lot of pollinators and predators. The insects are very possibly good guys.

The fkowers have not come yet so these insects are in the plant and neighbouring thyme too. They are tiny, i can't quite see them myself to take a picture. They fly off the camomile as soon as they are disturbed. All I can see is they are pale green. I don't see damage to the plant, just that when you touch it, lotsa of them come off at once and flies all over. I have a rather big patch of them too. Is this normal? Thanks.

Look up leaf hoppers.....just a guess since we really don't have much to go by.

Or try looking up aphids. Though not really flying types, they are tiny, can be green, and come en masse.

FataMorgana