This rare phenomenon is the unexpected by-product of last year's flooding which claimed the lives of close to 2,000 people in Pakistan. The heavy monsoon rains in July of last year left nearly one-fifth of Pakistan underwater and affected almost 20 million people. It also provoked millions of spiders to crawl into the trees to escape the water, coating the branches in a silk jacket. The rare site is now commonly seen in the southeastern corner of the country, near Karachi. It is thought that mosquitoes get caught in the webs, reducing the risk of malaria and benefitting the local people.