Robot mowers and hedgehogs: what the research says

Researchers at the Leibniz Institute for Zoo and Wildlife Research and Oxford University tested how robot mowers react to hedgehogs. They used dead hedgehogs and dummies, not live animals. In tests of 19 models, apart from one single incident, every mower had to physically touch a hedgehog carcass before it reacted. Separately, they recorded 370 cases of hedgehogs injured by cutting machines of all kinds; 47% did not survive.

The same research found less harm from front-wheel-drive designs, pivoting blades and skid plates that sit over the blades.

Five rules that matter more than any feature

1. Never mow at night. Set a daytime schedule, ideally finishing well before dusk.
2. Walk the lawn before the first run of the season, and check long grass and edges.
3. Keep a wild corner unmown and out of the mower's map.
4. Leave gaps of 13 cm by 13 cm under fences for hedgehog highways, as Hedgehog Street suggests.
5. Treat "animal detection" as a back-up, not a guarantee.

Features that help

The LUBA 3 AWD has a Wildlife Safety Mode that stops or slows mowing at night. ECOVACS says its GOAT cameras recognise hedgehogs. eufy says the E15 detects small animals and stops. None of these has been tested independently against the research above, so they earn only part of our safety score.

Sources

• Leibniz-IZW / Oxford WildCRU research summary (ScienceDaily, 23 Jan 2024)
• Hedgehog Street: research on robotic lawnmowers