A man stands near collapsed houses in Bhaktapur, on the outskirts of Kathmandu, on April 27, two days after a magnitude-7.8 earthquake hit Nepal. Aftershocks tend to get less frequent with time, scientists say, but not necessarily gentler. Prakash Mathema/AFP/Getty Images hide caption

itoggle caption Prakash Mathema/AFP/Getty Images

Callery pear trees in Pittsburgh. The smell of the invasive trees has been compared to rotting fish and other stinky things. Luke H. Gordon/Flickr hide caption

itoggle caption Luke H. Gordon/Flickr

"We could learn a lot from ants about how effective a noisy, messy system could be." — Deborah Gordon James Duncan Davidson/TED hide caption

itoggle caption James Duncan Davidson/TED