(left to right): DREW GURIAN; ISTOCK.COM/ARINDAM GHOSH; FABIO TEIXEIRA/AFP/GETTY IMAGES

Top stories: The science of false confessions, transforming blood types, and Brazil’s war on drugs

This psychologist explains why people confess to crimes they didn’t commit

False confessions are surprisingly common. That’s in part because standard interrogation techniques place suspects under psychological stresses from which a confession can seem like the only escape. Now, psychologists and other scientists studying interrogation methods and false confessions are placing more scrutiny on a piece of evidence once held as irrefutable in a court of law.

Type A blood converted to universal donor blood with help from bacterial enzymes

On any given day, hospitals across the United States burn through some 16,500 liters (35,000 pints) of donated blood for emergency surgeries, scheduled operations, and routine transfusions. But recipients can’t take just any blood: For a transfusion to be successful, the patient and donor blood types must be compatible. Now, researchers analyzing bacteria in the human gut have discovered that microbes there produce two enzymes that can convert the common type A into a more universally accepted type.

Brazilian government accused of suppressing data that would call its war on drugs into question

Is Brazil experiencing a drug epidemic? The answer to that question has spiraled into a legal battle between scientists and government officials over the release of a national drug use survey done by the renowned Oswaldo Cruz Foundation in Rio de Janeiro, Brazil. Researchers familiar with the study accuse government officials of suppressing publication of the survey because it contradicts a political assertion that drug abuse is a growing and widespread problem in Brazil.

Watch an ant rip apart a spiderweb to rescue a sibling

Ants are famous for putting themselves at risk for the wellbeing of their colony, but desert harvester ants are especially heroic. New research suggests the insects charge into spiderwebs to rescue their ensnared nestmates, sometimes ripping the silk apart to free them.

Spotted for the first time: a fish holding its breath underwater

Like us, fish need oxygen to survive. But to breathe, most pull oxygen-containing water into their mouths and pump it through their gill chambers before expelling it out of their gill slits. Now, for the first time, scientists have seen fish “holding” that breath, some for up to 4 minutes at a time.