Studying animals can help in understanding things about people. In mammals , testicles can be very big or very small in relation to the size of the animal itself. The size has to do with the amount of sperm that the male animal needs to make. Some types of male animal generally only have one sexual partner at a time and are called monogamous . Some types of animals generally live in a herd or flock where one male will have many female sexual partners. These males are called polygamous . More sperm is needed by polygamous males than by monogamous males. Polygamous males generally have larger testicles than monogamous males. The testicles grow larger to make more sperm.
The dish, purportedly cowboy fare,  is most commonly found served at festivals, amongst ranching families, or at certain specialty eating establishments and bars.  They are, however, also readily available at some public venues (., at Coors Field during Colorado Rockies baseball games). Eagle, Idaho , claims to have the "World's Largest Rocky Mountain Oyster Feed" during its Eagle Fun Days (now held the 2nd weekend in July).  Clinton, Montana , Deerfield, Michigan , Huntley, Illinois , Olean, Missouri , Severance, Colorado , and Tiro, Ohio also hold testicle festivals .  Rocky mountain oysters are sometimes served as a prank to those unaware of the origin of these "oysters". They are also considered to be an aphrodisiac by many people. 
NOT NECESSARILY TRUE . Faced with an unnatural rise in estrogen, some steroid users will then take a class of drugs called aromatase inhibitors , which are designed to block the production of estrogen in women with breast cancer, Weinerman says. That's right: It's a breast cancer drug. And aside from the obvious danger in further messing with hormones, guys who turn to aromatase inhibitors can have side effects like joint and muscle pain, the loss of sex drive, and the loss of bone density, which can then result in osteoporosis, according to a Susan G. Komen Foundation report .