A sofa floats in the polluted waters of Jacarepagua Lagoon, during a press tour in Rio de Janeiro, March 9, 2015. A press tour was organised by biologist Mario Moscatelli, to call attention to pollution on the waters of the lagoons which surround the Rio 2016 Olympic Park. (Photo by Ricardo Moraes/Reuters)

A protester runs from a jet of water shot from a police water cannon in the courtyard of the University of Santiago, during clashes between students and police, in Santiago, Chile, Thursday, May 14, 2015. In the capital and other cities across the country, high school and university students marched, for the second time this year, to demand education reform. (Photo by Luis Hidalgo/AP Photo)

A mahout splashes water on his elephant in the river Sabarmati on a hot summer day in Ahmedabad, India, May 20, 2015. (Photo by Amit Dave/Reuters)

A man drinks at a "colored" water cooler in a streetcar terminal in Oklahoma City, July 1939. (Photo by Reuters/Library of Congress)

A stranded cat swims through flood water searching for dry land June 16, 2008 in Oakville, Iowa. (Photo by Scott Olson/Getty Images)

A mahout splashes water on his elephant on a hot summer day in Ahmedabad, India on April 8, 2019. (Photo by Amit Dave/Reuters)

The performers prepare for the show. Fontana, a travelling water circus produced by Cirque Du Liban at Festival City in Dubai. (Photo by Chris Whiteoak/The National)

An unexpected side-effect of the flooding in parts of Pakistan has been that millions of spiders climbed up into the trees to escape the rising flood waters. Because of the scale of the flooding and the fact that the water has taken so long to recede, many trees have become cocooned in spiders’ webs.