—u/kawaiikaeru23
“The [British biologist Lancelot Hogben] found that injecting the urine of a pregnant human into the frog’s hind leg worked as an effective pregnancy test. If the woman who supplied the urine was pregnant, the frog would ovulate and produce eggs.”
—u/DC2413
Source: https://www.buzzfeed.com/hannahmarder/weird-facts-that-sound-fake-but-are-actually-true