An echidna placed in a box is likely to remain there for under a minute . A Pouch Young, also called a 'puggle'. This lighter coloured pouch youngster is starting to get his spines. Not surprisingly, when the spines develop, the mother kicks them out of the pouch. Why not, Echidna hypernate much of the winter in Mountainous areas, but do wake to forage every few weeks.
Echidnas are also surprisingly good swimmers, and like a dip, especially on hot days.
This is a very common behaviour. It takes only second for a threatened Echidna to dig straight down so only its prickly back is exposed to an attacker. This closeup of the hind foot of the Echidna shows the elongated third claw used for grooming. I have available a photograph of the penis of the male echidna, which, if you care to look, is quite an unusual organ. Since not everyone cares to be confronted with Echidna private parts, you will have to link through if you wish to see it.