Honeybees, Instruments of War

• Believe it or not, honeybees were instruments of war in the times of ancient Greeks and Romans. Before box hives were invented to keep bees, they were kept in twig, straw or clay vessels that could be thrown at enemies or dropped on them from above. In attacks on medieval castles, catapults were used to throw bee “bombs” over castle walls. “By the time they reached their targets, the… bees were outraged, ready to explode in a fury of stings.” An alarm pheromone released by some of the bees also helped drive the bees into a stinging frenzy. (Bishop, H., 2005, Robbing the Bees, Free Press, NY; Waldbauer, G., 2012, How Not to be Eaten, The Insects Fight Back, U. of California Press, Berkeley)

• How does a scientist determine when a hamster is depressed? First, when a hamster loses its intense preference for sweet drinks. In other words, the animal fails to derive pleasure from this activity. Second, a hamster is placed in a pool of water and the time it takes to extricate itself is measured. A “depressed” hamster does not struggle much and is content to just float (up to 10 times as long as an animal that is not “depressed”).

So what might hamster “depression” tell us about human depression? A recent study of 13 hamsters showed that animals exposed to normal nighttime darkness showed no signs of depression. On the other hand, when hamsters were exposed to dim light at night for four weeks they became depressed. Humans with major depression show a reduction in the number of synaptic contacts in the hippocampus, a part of the limbic system that plays a role in depression. Examinations of the brains of depressed hamsters show similar changes. When depressed hamsters were returned to a normal nighttime dark cycle, their depression lifted, so it is possible that a depressed person might find relief by ensuring that their bedroom is completely dark at night. (Molecular Psychiatry, on line, July 24, 2012; Science News, Aug. 25, 2012)

• Many tropical preserves have been established to protect biodiversity, but evidence is accumulating that many are in decline as a result of conditions in lands next to the parks. Logging, deforestation and fires just outside a park have strong effects on animal and plant life in the preserve. Air and water pollution were found to be less important. More than 200 scientists authored a key report on the status of tropical preserves. They found that about four-fifths of them were in a declining mode. (Science News, Aug. 25, 2012; Laurence, et al, 2012, Nature, July 25, 2012)

• Terrestrial hermit crabs live in abandoned snail shells, and while the front part of the body is similar to that of a crayfish, the rear (abdominal) region is naked-looking and lacks the hardened exoskeleton of the front end. The abdominal end is forced into a snail shell, where it anchors the crab. As the crab grows, it is obliged to seek a larger snail shell, and several older crabs are known to gang-up on a crab living contentedly in a shell they covet. They forcibly pry the occupant out of its shell so one of them can move in. We call it eviction. (National Wildlife, Jan. 14, 2013)