Answer: the following observation -- rats have disproportionally large testicles!

So how does that translate for humans? Assuming that the same ratio existed for a 200 lb man, for example, then that man -- unfortunate as it is -- would be schlepping around 4.2 lbs of testicles! To help you appreciate the sheer weight of 4.2 lbs, consider having to schlep between your legs (for life, that is) one of the following:
13 baseballs
10 softballs
22 CDs in standard jewel cases
9 VHS tapes in cardboard cases
a 5 lb bag of sugar minus several cups
a 2 liter bottle of your favorite soda
Research does not always lead to application, but does at times stir a greater sense of appreciation -- for all things both great and small! Likewise, as a runner who does not like the chronic chafing that often accompanies a long run, this serendipitous rodent observation helps me appreciate the fact that size is not always better!