Amphisbaenians, or worm lizards, are small burrowing reptiles with a highly specialized diet: arthropods, and in some species, gastropods. Most of what we know about their feeding habits comes from dissecting the gut contents of preserved museum specimens — a method that, by nature, only ever gives us a static snapshot.

A short note recently published in Acta Herpetologica offers something different: a living, ongoing account of a worm lizard eating something it really shouldn't.

In 2022, in Goianesia (Central-West Brazil), a worm lizard was observed eating cookie crumbs. The observer — who has no scientific background or formal training in biology — kept offering the animal bread and cookie crumbs afterward, documenting each encounter with photos and video over several months.

Although the media quality is modest, the recurring visits are hypothesized to involve the same individual, tentatively identified as either Amphisbaena vermicularis or A. mertensii. The behavior's persistence over time is interpreted as a learned habit rather than a one-off accident.

This kind of unusual feeding has been documented before in other lizards, but remains a noteworthy phenomenon known as allotriophagy — a term that, in veterinary contexts, also covers the consumption of non-edible items. Eating human food provides no real nutritional value to the animal, and the behavior is generally thought to stem from either nutritional deficiency or opportunistic scavenging on waste, a pattern common among wild animals living in urban environments.

More importantly, it is no't harmless: allotriophagy can disrupt gut microbiota, weaken immune function, and alter an animal's physiology and behavior over time.

Curious to learn more? Read the full paper here.

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