NPR News

Michigan Sen. Carl Levin announced today that he would not seek reelection in 2014. Levin chairs the Armed Services Committee.

In a statement, he called the decision "extremely difficult."

The Education Department has launched an investigation into discipline rates in Seattle public schools.

Students of color have long been punished in far higher numbers than white students in Seattle, but now the department's Office for Civil Rights is looking at whether black students are disciplined more frequently and more harshly than white students for the same behavior.

Who knew that the flower nectar of citrus plants — including some varieties of grapefruit, lemon and oranges — contains caffeine? As does the nectar of coffee plant flowers.

And when honeybees feed on caffeine-containing nectar, it turns out, the caffeine buzz seems to improve their memories — or their motivations for going back for more.

"It is surprising," says Geraldine Wright at Newcastle University in the the U.K., the lead researcher of a new honeybee study published in the journal Science.

A new flood of Syrian refugees is streaming into southern Turkey after the Syrian air force bombed the city of Raqqa, a provincial capital that the government lost control of earlier this week.

The Syrian rebels overran Raqqa, capturing several high-ranking prisoners, including the provincial governor. Many residents supported the rebels, but when the airstrikes began, they packed in a hurry and fled, believing it was safer to make a dash for the border than stay at home.

The Senate easily confirmed the nomination of John Brennan as CIA director, that following the dramatics of Sen. Rand Paul, who filibustered against it for nearly 13 hours on Wednesday night. Is this the dawn of a new era of these, old-school, "talking" filibusters? Tamara Keith talks to Audie Cornish.

Melissa Block and Audie Cornish read from the latest listener letters, which include praise for Wednesday's critique of the Dow Jones Industrial Average. They also have a correction to a story regarding where the Model-T Ford was made.