That moment when you realise something without arms or legs is a better climber than you:
These wall-scaling snakes are known as "boomslangs" – and they're on the hunt for an avian snack. Filmed by Katy Pepper at her home on the east coast of South Africa earlier this week, the reptiles' climbing prowess is on show as they raid a swallow's nest in search of chicks or eggs to eat.
The snake making its ascent is male, distinguished by green and black markings, while its duller, grey accomplice is a female. According to local herpetologist Johan Marais, it's not unusual to see two or more boomslangs raiding a nest. Adults of the species (like the two in this clip) can reach lengths of over two metres (6.5 feet), and are identified by their unusually large eyes.
The name boomslang means "tree snake", so it's really no surprise that these nest-raiders are accomplished climbers. Boomslangs spend a lot of their time in the canopy, and can extend as much as half of the body into the air when stretching between branches.
And it's probably a good thing that Pepper kept her distance while filming the visitors: although boomslang bites are very rare, they can be fatal. Drop for drop, boomslang venom is considered the most potent in Africa, beating even toxic heavyweights like the black mamba.
A member of the Colubridae family, the boomslang is armed with fangs mounted in the rear of the jaw. While most of its relatives have weak venom and fangs too small to pose a threat to humans, this species (Dispholidus typus) defies colubrid convention. The deadly snakes can open their mouths to almost 180° when biting, often striking more than once to inject a slow-acting haemotoxic venom.
Fortunately for Pepper, this pair was far more interested in the birds.
Header image: Maarten/Flickr