Monarch butterflies have magnitite (a mineral) inside their heads and this helps them determine 'North', just like a magnet.
Blue for danger
Blue for danger Scientists have developed a new type of plant
which has properties that allow easy detection of exposure to
dangerous levels of radiation. The plants have been genetically
modified so that when samples of the plant tissue are examined in
the laboratory, they turn blue if the plant has previously been
exposed to dangerous radiation levels. 28 NOVEMBER 1998, P. 22
Cool Articles
