An egg-laying mammal. Solitary. Echidnas shelter in burrows or crevices among rocks and emerge in the afternoon and at night. The dorsal side is fully covered with spines up to 60mm in length. When disturbed, they dig rapidly into the ground and cling to it with their strong claws on both hind and forefeet. They can also roll up into spiny balls to avoid attack. Echidnas feed mainly on ants and termites with the sticky and long tongue, which can extend up to 18 cm beyond the snout. They are therefore sometimes called the Spiny Anteaters. Breeding female lays one egg into the temporary pouch on her abdomen. The egg will hatch after seven to ten days. The young is nourished with milk in the pouch and will leave after about three weeks once the spines develop.