mosquito repellent: A bird found in Alaska is believed to emit a natural mosquito repellent, according to Hector Douglas, a researcher at the University of Alaska, Fairbanks. The crested auklet gives off a citrus smell that repels mosquitoes and pests such as ticks and lice.

An analysis of the chemicals that make up the auklet's "odorant' revealed that most are available commercially. He then tested their repellent properties using mosquitoes specially bred at a research lab in Florida for their aggressive tendencies. Douglas dabbed test samples on filter paper, attached that paper to his hand, then put it in a cage with hungry mosquitoes. It was clear the auklet samples kept mosquitoes away.

urine power: Physicists in Singapore have created the first urine-powered paper battery. The credit-card sized unit could be a useful power source for cheap healthcare test kits for diseases like diabetes, and could even be used in emergency situations to power a cellphone, they say.

Testing urine can reveal the identity of illnesses, and the new paper battery could allow the sample being tested to also power the diagnostic device, says Ki Bang Lee, at the Institute of Bioengineering and Nanotechnology in Singapore.

The urine-powered battery was able to generate a voltage of about 1.5 volts