Because of the flood that happened last year in Pakistan, millions of spiders that originally lived on the ground were driven up into the trees to escape the water... It took a long time for the water to recede and therefore, in order to feed, the spiders built massive webs around the trees... It's like the trees were cocooned... 

Though it appears as if they are sets for a horror movie, however, these webs are actually helping the people of Pakistan to win the battle against malaria... The villagers reported that they no longer have to worry about massive mosquito attack during sleep...

Cool huh?

More pictures here