How do jellyfishes sting you if they are like 90% water?

Question: How do jellyfishes sting you if they are like 90% water?
- Keywords:
  jellyfish,
  ocean,
  sting,
  water
Asked by to Daren, Lynne, Phillip, Simon on 20 Jun 2014. This question was also asked by .
- Daren Fearon answered on 20 Jun 2014:
  
  Humans are over 50% water and yet we can do all kinds of amazing things! Jellyfish are very simple creatures with no brains, blood or hearts. They have a nervous system or nerve net that allows them to detect light and respond to their environment and a very simple digestive system. They don’t seek out food and there tentacles which they use to sting can be used to catch food by injecting toxins. They also use this sting as a defence mechanism to avoid being eaten themselves.

Question: How do jellyfishes sting you if they are like 90% water?