Envy is often associated with the color green, as in "green with envy", and yellow. Yellow is the color of ambivalence and contradiction; a color associated with optimism and amusement; but also with betrayal, duplicity, and jealousy. The phrase "green-eyed monster" refers to an individual whose current actions appear motivated by jealousy not envy. This is based on a line from Shakespeare's "Othello". Shakespeare mentions it also in "The Merchant of Venice" when Portia states: "How all the other passions fleet to air, as doubtful thoughts and rash embraced despair and shuddering fear and green-eyed jealousy!" The character Envy from Fullmetal
Green-eyed tree frog only be heard from short distances. Oftentimes the male's mating call can sound like a quiet tapping noise. Being semi-aquatic, green-eyed tree frogs call from vegetation in water and have two types of calls: harsh trill and untrilled. Some males choose to call in groups of a hundred or more and can be found harmonizing at night. During these mating calls, the males are typically located in vegetation in water. Breeding season occurs during May and July, corresponding with the early rain season, though it has been reported that breeding might occur year-round. Breeding season in Australia starts in August.