Sounds like spittle bug to me! You can just hose them off.

Here is a link that might be useful: Spit bug

I agree with heathen1. They're very common on lavender for some reason. I've never seen enough on one plant to do it serious damage, but they can distort the stem they're on, so if you want the maximum flowers from your plants, get rid of the bugs.

Spittle bugs....don't just hose them off, squish the bug that's in the center of the foam.

Could it not be frog sperm?

Hose them off well and use some form of organic pesticide i use Pyrethrum

Wow that is strange I came here tonight to post a question about the same "spit" only its on my rosemary plants that are also well established...
these were all over the plants (5 of them) I have grapes growing very near them should I be worried about the grapes?
Thanks for any help

Spray the grapes with neem and they should be fine. Grapes usually have only disease issues, but bugs do chew the leaves too. Sometimes these 'spits' are insect eggs and will hatch soon.

Spittle bugs also like Basel, I guess they like smelly plants.

In the English language, when things 'smell' good they are not described as 'smelly' as this is an adjective with negative connotation. They are fragrant or scented. Call it advice for the next time you want to bring back a thread from the dead.