Do you want to go to the park? Mango Doucleff, of San Francisco, responds to her favorite command by perking up her ears and tilting her head. Michaeleen Doucleff/NPR hide caption

itoggle caption Michaeleen Doucleff/NPR

A 40-pound tom turkey flaps his wing as Chris Conley carries him to a pen at Raymond's Turkey Farm in Methuen, Mass., on Friday. The farm raises approximately 20,000 broad-breasted white turkeys per year. Elise Amendola/AP hide caption

itoggle caption Elise Amendola/AP

A turkey vulture makes quick work of a dead rabbit at Martin Luther King Jr. Regional Shoreline park in Oakland, Calif. Sebastian Kennerknecht/Minden/Corbis hide caption

itoggle caption Sebastian Kennerknecht/Minden/Corbis

A tangle of protein (green) in this scanning electron micrograph of a brain cell of an Alzheimer's patient lies within the cytoplasm (blue) of the cell. The tangle consists of clumps of a toxic form of tau. Thomas J. Deerinck/Corbis hide caption

itoggle caption Thomas J. Deerinck/Corbis

A nurse adjusts the position of a patient's arm during dialysis treatment. The treatment requires trained staff that weren't readily available in the aftermath of Hurricane Sandy. Michael Donne/Science Source hide caption

itoggle caption Michael Donne/Science Source

This is a re-creation of a color plate from Interaction of Color, by Josef Albers. The two X's are are exactly the same — it's the different backgrounds that make them look like very different colors. Source: Josef Albers Interaction of Color hide caption

itoggle caption Source: Josef Albers Interaction of Color

Laundry detergent makers recently introduced miniature packets, but doctors across the country say children are confusing the tiny, brightly colored packets with candy and swallowing them. Pat Sullivan/Associated Press hide caption

itoggle caption Pat Sullivan/Associated Press

One of these penguins is not like the others — the chick in front is really a rover, designed by filmmakers and used by scientists to gather data. Huddle/John Downer Productions/BBC hide caption

itoggle caption Huddle/John Downer Productions/BBC

A python embryo turns its leg cells into a pair of penises. Researchers now believe that signals from the embryonic gut trigger the development of the penis in many different species. Patrick Tschopp/Harvard Medical School/Department of Genetics hide caption

itoggle caption Patrick Tschopp/Harvard Medical School/Department of Genetics

David Roberts says the Cyber-Enhanced Working Dog harness will allow humans to monitor dogs' physical and emotional states remotely, such as in search and rescue operations. Becky Kirkland/North Carolina State University hide caption

itoggle caption Becky Kirkland/North Carolina State University