This is my kind of trivia.
For years, biologists have puzzled at the strange shape of rodent sperm. As opposed to the sperm of most other mammals, which have paddle-shaped heads, the sperm heads of many rat and mouse species are curved like scythes. About 10 years ago, scientists studying the European woodmouse discovered that these hooks allow groups of up to 100 sperm to attach to each other, and that these "sperm trains" moved faster than sperm swimming alone.
You know the rest. It's another illustration of selection of the fittest. Something like cutting the dandelions over a single summer leaves only the ones with short stems growing at the end of the year...the ones too short to be taken out by the mower blade.
Next come the labels that tell us that this is not evidence of evolution. It's just another tool that Satan uses to confuse the faithful.