What works to kill/prevent no see-ems/mosquito bites?

We use a homeopathic gel called "Ssting-Sstop" by B&H. It doesn't prevent bites or stings but for many folks it is remarkable in reducing the pain and itching after-the-fact.

So something named "Sting Stop" doesn't prevent stings? That's the definition of homeopathy, isn't it?
😀

Well, it depends on what the meaning of "Sting" is!

verb:

1.
wound or pierce with a sting.
"he was stung by a jellyfish"
synonyms: prick, wound, bite; poison
"she was stung by a scorpion"

2.
feel or cause to feel a sharp tingling or burning pain or sensation.
"her eyes stung"
synonyms: smart, burn, hurt, be irritated, be sore
"the smoke made her eyes sting"

So it helps with the latter but not the first.

BTW- I just tried it and it soothed me from your rejoinder!