Hedgehog Crash Test Dummies Help Safety Test Robotic Lawnmowers

European hedgehogs might be a popular garden visitor, but having to share space with humans can sometimes put them at risk, including from the smart tech that keeps our lawns looking tidy. New research has highlighted how some robotic lawnmowers could cause harm to hedgehogs, but thankfully, it’s also come up with a creative safety test solution.

That solution came in the form of a hedgehog “crash test dummy”. Developed by a team led by Dr Sophie Lund Rasmussen from the University of Oxford, the dummy is made from a soft rubbery plastic that’s designed to mimic the squishy body of a real hedgehog – and of course, its iconic spines.

To create a safety test using this dummy, it was first important to determine how hedgehogs reacted when faced with a robotic lawnmower. Working in an enclosed environment with rescued hedgehogs that were now ready for release, the research team tested the responses of hedgehogs to a bladeless robotic lawnmower that was stopped 50 centimeters (20 inches) away.

The test setup for the encounter tests between live hedgehogs and a disarmed robotic lawnmower, which was stopped before reaching the hedgehogs.
Image credit: Sophie Lund Rasmussen

They found that the creatures either ran away, stood in front of the lawnmower slightly curled up, or started sniffing it. From this, the researchers could identify the best positions to put the hedgehog crash test dummy in to safety test a robotic mower, with the test itself then revealing if the device could avoid a hedgehog and if not, the level of damage it would cause to the animal.


“Cut injuries from robotic lawnmowers are placing an enormous burden on many hedgehog care centres and using up important resources, as these injuries often require above-average care and treatment,” said study co-author Dr Anne Berger in a statement. “Moreover, the majority of hedgehogs with cut injuries are found days or weeks after the accident happened and therefore have to endure considerable suffering, pain and harm until they are found.” 

It’s hoped that the new safety test will lead to the development of more hedgehog-friendly robotic lawnmowers, something that Dr Rasmussen told IFLScience is already in the works.

”Our research has identified a potential threat to the hedgehogs, as some models of robotic lawn mowers – but not all – can be harmful to hedgehogs. Therefore, we have formed collaborations with industry partners to find solutions to this challenge by designing hedgehog-friendly robotic lawn mowers based on the knowledge gained through the research,” the researcher explained.

With hedgehog numbers having been in decline for a while, this research hopefully comes as the start of some good news for these firm favorites of the European garden. 

The two studies describing the findings are published in the journal Animals, here and here.

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