As the deer turned its head away from me, I slowly raised my muzzle-loading rifle and took aim. Suddenly, I was startled by a loud snort. I lowered my rifle and watched as two deer waved their white tails as if saying goodbye to me.

Although I hadn’t seen the second deer, it was apparent that it had been watching me. An alarm was given for the deer to flee to safety. Recently I read that the visual white tail flash of the deer’s tail has been suggested as an alarm signal to the predator that they have been detected.

Deer hunters know that a deer has two tarsal glands, one inside each hind leg at the hock joint: two metatarsal glands, one on the outside of each hind leg, between the hock and the foot. These glands release a scent conveying excitement or danger. Even though deer are not in the immediate area and cannot hear the loud snorts or see the white tails, they pick up the scent and know that danger is near. A deer also has four interdigital, one between the toes on each foot, which produce odors that allow deer to trail each other by smell.

Hunters are aware of the many alarms given off by birds and animals, and here are a few: turkeys give off a rapid putting call; squirrels give off a kuk, kuk, kuk call or a rapid barking call; crows and blue jays will scold, and when they do the other animals pay attention.

Alarm calls are often high-frequency sounds since these sounds are harder to locate. Beavers slap their tails on the water to warn of danger to other beavers in the colony. I’m sure we have all heard the alarm call of the blackbird.

Insects also use smells as alarm signals. Pheromones are scents and other chemicals used for communication. Bees, wasps, and ants produce pheromones when they sting. The pheromones alert other insects to come and help defend the nest. Recently, I killed a stink bug, which gave off its familiar odor, a warning to other bugs in the area.

I have a book, entitled “Bats Sing, Mice Giggle” by Karen Shanor (PhD) and Jagmeet Kanwal (PhD). This book allows a fascinating look into nature, with one chapter on alarms given by one animal to warn other animals of danger.

We’ve all heard and enjoyed the pleasant chick-adee call of the black-capped chickadee; however, this call is also used as an alarm by adding “dee” to the call. For example, the more “dee’s” at the end of the call means a higher degree of danger. Not only will other black-capped chickadees heed the alert alarm, the nuthatch, titmouse, and other small birds that forage with the chickadee flock will also respond to the call, knowing that danger is near. Researchers have found that the chickadee has warning calls for different types of predators. Along with the number of “dees,” a high pitch “seet” call is given for flying predators.

When other birds hear this “seet” call they head for heavy cover. Most of us have at one time seen a pair of robins trying to drive a crow away from their nest, with their alarm calls bringing birds of other species to help.

Researchers have found that plants also give off warnings by generating an electric signal that is picked up by other plants and insects. In one study, researchers hooked up electrodes to the leaves and stems of a philodendron plant. Ten people were selected to enter the room, one at a time, and told to stand next to the plant and to touch the plant. The electric activity of the plant went up, but not by much.

Then, one of the ten was told to tear off a few leaves from the plant, and this caused the electric activity in the plant to rise significantly. On the next day, all ten people returned to the room, one by one, to stand by the plant. When the person that damaged the leaves stood by the plant, the plant’s electric activity zoomed to a high level, even though no damage had been done on that day.

Amazing. Yes, but even more amazing is that on the third day, the researchers put other plants in the room with the philodendron. When the “leaf tearer” entered the room the philodendron plant sent out a warning signal to the other plants in the room, and the plants picked up the alarm. On the fourth day of the experiment, “the leaf tearer” entered the room and the electric activity of all the plants increased almost in unison.

I found this hard to believe and decided to do research on how plants react to danger. I read that according to botanists, the smell of newly mown grass is caused by gases emitted from each injured blade of grass. Chopped grass releases a long list of volatile organic compounds, including methane (swamp gas), acetone (as in nail-polish remover), ethanol (grain alcohol) and acetaldehyde (a chemical similar to the toxic preservative formaldehyde).

The grass produces these volatile compounds within seconds of being cut. Botanists suspect that the chemicals have an antimicrobial action protecting the cut part from invasion by microbes already teeming on the leaf surface.

Some scientists think that cut grass is a kind of chemical polluter. Compounds from wounded grass react with nitrogen oxides, helping to form more ozone near the ground, where it is not wanted. Grass that has been cut and left drying on the lawn releases more compounds, perhaps as much as ten times the amount of cut grass still rooted in the ground.

So, the pollution given off by our lawns could be worse than the pollution coming from our lawnmowers.

Now don’t take this as a reason not to cut your grass next summer.