Echidna's mate in winter and trains where males follow the female is the beginning of quite a bizarre mating behaviour. Trains can last for up to 6 weeks, and can have up to ten males following a female though 3 or 4 is the usual number. While males occasionally nudge the female there is not much action until the female is ready to mate. The males then dig a trench next to her and push each other to be the one to occupy this nuptial bed.