Research chimps enjoy retirement -- at last

Feb. 19, 2013: Two chimps walk together at Chimp Haven in Keithville, La. (AP Photo/Gerald Herbert)

Feb. 19, 2013: A baby chimp's hands, left, are seen touching the hands of other chimps at Chimp Haven in Keithville, La. (AP Photo/Gerald Herbert)

Feb. 18, 2013: A chimp climbs a pine tree at Chimp Haven in Keithville, La. (AP Photo/Gerald Herbert)

Feb. 19, 2013: A mother chimp holds a piece of lettuce in her mouth as she carries her baby at Chimp Haven in Keithville, La. (AP Photo/Gerald Herbert)

Feb. 18, 2013: The hands of a baby chimp cling to its mother as she walks at Chimp Haven in Keithville, La. (AP Photo/Gerald Herbert)

Feb. 19, 2013: A mother chimp carries her baby at Chimp Haven in Keithville, La. (AP Photo/Gerald Herbert)

Feb. 19, 2013: A mother chimp relaxes with her baby at Chimp Haven in Keithville, La. (AP Photo/Gerald Herbert)

Feb. 18, 2013: An adult chimp plays with a young chimp at Chimp Haven in Keithville, La. (AP Photo/Gerald Herbert)

Feb. 19, 2013: Adrienne Mrsny, an animal care specialist, feeds chimps in a section reserved for HIV-infected chimps at Chimp Haven in Keithville, La. (AP Photo/Gerald Herbert)

Feb. 19, 2013: Two chimps tussle for food at Chimp Haven in Keithville, La.. (AP Photo/Gerald Herbert)

Feb. 19, 2013: A baby chimp shows a variety of expressions as it sits in its mother's arms at Chimp Haven in Keithville, La. (AP Photo/Gerald Herbert)

Feb. 19, 2013: Chimps use sticks to poke into a mock termite mound to taste a sweet substance placed in the mound by keepers at Chimp Haven in Keithville, La. (AP Photo/Janet McConnaughey)