Snake traps get smarter: new designs keep out the wrong reptiles

Scientists are tackling a sneaky problem: invasive snakes that eat native lizards and upset local ecosystems. The California kingsnake, originally from North America, has spread to places like the Canary Islands, where it hunts rare reptiles. Traditional traps catch everything, including harmless local species, making control messy and ineffective.A fresh approach tested different tunnel shapes—funnels, spinning doors, curved paths, and straight slots—to let only the invasive snake enter. In lab tests, every shape worked well, steering the kingsnake in while keeping other reptiles out. When moved outside, the same tunnels still performed strongly, cutting unwanted catches by more than 98 percent compared to old-style traps. Not everything was perfect. Smaller animals sometimes slipped through, especially in wider tunnels. But when researchers narrowed the entrance to 21 by 21 millimeters and fine-tuned the tunnel designs, the traps became much more reliable. This mix of size limits and clever shapes could be copied in other regions fighting snake invasions.