A wild New Caledonian crow demonstrates one of several methods in the species’ repertoire to add a bit of curve to twigs. These tweaked tools can snag food out of hard-to-reach spots. Read more: http://ow.ly/ofqP303grCw | Science News Magazine

A new experiment reveals, in a nutshell, why the largest particles in some mixtures tend to gather at the top. This phenomenon is known as the Brazil nut effect. (Brazil nuts are in yellow; peanuts are in red in the left clip and transparent on the right.) Learn more: https://www.sciencenews.org/article/brazil-nut-effect-mixed-nuts-xray-scan-physics | Science News Magazine

Researchers captured E. coli bacteria in the act of becoming resistant to the antibiotic tetracycline. Some bacteria already contained a circular piece of DNA, called a plasmid, which carries antibiotic-resistance genes. Those resistant cells (green) pass the plasmid to sensitive cells (red). Once the plasmid has transferred (yellow dots), sensitive bacteria begin making proteins that make the microbes resistant to the antibiotic. The bacteria turn increasingly green as they become resistant to