Snowy Tree Crickets and their cousins double as thermometers and wee garden predators, dining on aphids and other wee beasties.
Weather conditions, both hot and cold, affect the speed at which they rub the base of their wings together and consequently regulate their rate of chirping. Listen for their tell-tale high pitch triple chirp sound in the early evening. Being in Canada, our crickets chirp in Celsius. Simply count the number of chirps over a seven second period and add five to learn your local temperature.
If didn't bring your calculator with you into the woods and you're still operating in old-skool Fahrenheit, ie. those in the United States, the Bahamas, Belize, the Cayman Islands and Liberia can use this handy conversion. Double the temperature in Celsius, add 32 you'll get the approximate temperature in Fahrenheit.