What is in stinging nettles that makes it sting if you touch them? - Secondary 11

Question: What is in stinging nettles that makes it sting if you touch them?
- Keywords:
  plant,
  stinging nettles
Asked by kamilo12 to clairemarieroberts, Faye, Martin, Mus, Pete on 23 Apr 2012.
- Pete Etchells answered on 23 Apr 2012:
  
  Great question kamilo12! Nettle leaves have lots of little hairs on them. When you touch the leaf, the hairs break off into your skin, and sort of act like little needles, by injecting you with a tiny amount of various chemicals such as serotonin, acetylcholine and formic acid. This causes a burning feeling, which we call the sting.