The nearby town wanted a green way to remove garbage... so in their infinite wisdom, they started experiments with ants. Lets just say their experiments didn't go too well... They're trying to contain this mess but you'll need to get across that ant hill to win this battle.
You might try and get slick and try to cross the river... but rumor has it the russians had an interest in the ant project. Try and cross at your own risk.
The ants also learned how to control people! The people trying to keep the ants contained are now under their control.