Echidna

The strangest mammal, the Echidna

Exploring nature's adorable oddity

A mammal that lays eggs?

The traits of a furred, milk-feeding mammal + the traits of an egg-laying reptile or bird

= a rare monotreme with both of these traits.

On Earth, only the echidna and the platypus exist as monotremes!

A super body built for survival

• An electric-sensing nose — its eyesight is weak, but the sensors on its nose tip detect the faintest movement of prey underground.
• Keratin spines — its whole body is armored with hard spines, evolved from fur, up to 5cm long.
• A powerful digger — it digs through soil quickly using its spongy soft foot pads and sturdy claws.

A toothless insect hunter

• Zero teeth — it uses its long, sticky tongue to lap up ants and termites.
• An acid-free stomach — unlike other mammals, its stomach is nearly neutral (pH 6.2–7.4), with almost no stomach acid.
• A natural blender — the soil and sand it swallows grind against the stomach's powerful muscles, crushing insects into small pieces.

'Snot bubbles' instead of sweat

• No sweat glands — echidnas can't lower their body temperature by sweating or panting.
• Cooling through the nose — when it's hot, it forms bubbles of saliva and mucus at its nose tip, cooling itself as they evaporate.
• Low body temperature — its normal body temperature is already quite low, at 30–32°C, making it vulnerable to extreme heat.

A perfect, impenetrable defense

• When it senses danger, instead of running away, it freezes instantly on the spot.
• Using its very short spine, it curls into a perfect ball, hiding its soft belly, and burrows into the ground.

The strange 'mating train'

• Lining up for love — during the breeding season, up to 10 males follow closely behind a single female.
• A 4-week march — this odd train procession can last anywhere from a few days to as long as 4 weeks.
• An unusual anatomy — males have a unique reptile-like reproductive organ with four heads.

A rubbery egg the size of a grape

• A small, soft egg — females lay just one egg a year. This egg has a soft, rubbery shell and is about the size of a grape.
• A temporary pouch — the egg rolls directly into a 'temporary pouch' formed by the contraction of the female's abdominal muscles.
• A 10-day wait — inside this safe, warm pouch, the baby hatches in just 10 days.

Hello, baby 'puggle'!

• A spineless jelly — the newly hatched baby has no spines or fur and no eyesight, in a very fragile state.
• Rapid growth — it stays inside the mother's pouch for about 7 weeks, growing safely until its spines start to grow in.

Special nursing without nipples

• Milk patches — mothers have no nipples. Instead, milk seeps out through special skin glands called milk patches.
• Pink milk — rich in iron, the milk has a pink tint, and the baby laps it up with its beak.
• A microbial shield — since babies don't receive microbes at birth due to the eggshell, antimicrobial substances in the milk and skin help build up the baby's immunity.

Comparing relatives: short-beaked vs long-beaked

• Short-beaked echidna (Tachyglossus)
  • Diet — ants, termites
  • Habitat — found across Australia (most common)
  • Features — small, round body, strong digging power
• Sir David's long-beaked echidna (Zaglossus)
  • Diet — earthworms
  • Habitat — the Cyclops Mountains of New Guinea
  • Features — 5 front claws, critically endangered

Slow but tough vitality

• With a slow metabolism and low body temperature, echidnas boast an amazing lifespan — 10 years in the wild, and up to 49 years in captivity.
• These small, remarkable spiny creatures have guarded the Earth for tens of millions of years, and they need our care to keep living safely for years to come.