Subject: How can ants live underwater?

Once I saw a group of fire ants crawling along the bottom of a water bowl for 
hours seemingly unaffected.  At the time I assumed they were somehow "holding 
their breath" or carrying air bubbles with them.  That would explain short 
term survival, but I recently saw a commercial that said they can live for up 
to 2 weeks underwater.  How do normally air breathing ants adapt for an 
aquatic lifestyle, and what kills them?  Do they absorb oxygen dissolved in 
water or respire through some other process?  Thank you for your time.

Re: How can ants live underwater?