I came across these four (at least I think there’s four here) echidnas at rest in a burnt out tree stump not too far from the house. At breeding time, the female echidna may find several males trailing alongside or behind her to form an “echidna train“. Given this, it’s most likely that the female is the animal furthest into the stump (and most buried), and the three males are behind her (and closer to the camera).