Reproductive tract of a female mouse (IMAGE) eLife Caption Three-dimensional image showing the head (green) and tail (red) of sperm cells travelling towards the fertilisation site (to the left side of the image) in the reproductive tract (blue cells) of a female mouse Credit Lukas Ded (CC BY 4.0) Usage Restrictions This image is free to be reused, as long as it is credited as appropriate License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.