Hedgehog numbers across the UK are falling, particularly in the east of the country, a survey has found.
Hedgehogs do not like tidy gardens
According to the Mammals Trust UK, hedgehog numbers have dropped steeply since 2001, when a survey to spot animals on roads began.
The idea behind the study is that the quantity of hedgehogs on roads can indicate the size of the UK population.
Experts say that, amongst other factors, tidier decked gardens are responsible for the animals' decline.
Dr Valerie Keeble of the Mammals Trust UK (MTUK) said people should leave their gardens a bit haphazard to encourage the animals' return.
"Don't be too tidy in your garden," she told BBC News. "Leave some rough areas and leave a few bushes and hedges, and twigs on the ground.
"Make sure there is plenty of stuff for them to make their nests with; leave leaves and twigs lying about, that kind of thing."
In England as a whole, hedgehog numbers along roads have dropped by over 20% since 2001, the Mammals on Roads survey has found.
"It is of great concern to see that the decline in hedgehog numbers is continuing," said Jill Nelson, chief executive of MTUK.
"However we hope the public will react positively to this unfortunate news by choosing to assist us by taking part in this year's survey."
This year's survey begins on Friday and will run to the end of September. Anybody using roads around the UK is asked to take note of how many hedgehogs they see - dead or alive - on stretches of single carriageway roads, on journeys of 20 miles or more.
Dr Paul Bright of Royal Holloway, University of London, said: "It is important to continue to monitor hedgehogs and determine why their numbers are changing, not only to ensure that we safeguard this species in the future, but also because if the hedgehog is declining so will many other species with similar needs.
"Mammals on Roads is currently the only survey able to monitor hedgehog numbers on a national scale."
If you would like to take part in this survey, or would like to find out more, call MTUK on 0207498 5262