Wildlife experts say the mild weather is putting hedgehogs lives at risk, because it's making them come out of hibernation early.
This is risky for the creatures because their usual food - like bugs and beetles - are hidden away at this time of year.
This could make them underweight, which is dangerous for them if the temperatures drop as they need the extra body fat to keep them warm.
Simon Cowell from the Wildlife Aid Foundation said families should keep an eye out for hedgehogs and leave them some food.
He said: "The chances of an underweight hedgehog surviving hibernation are zero"
"A hedgehog brought to us in this condition needs months of specialist care and plenty of food to restore it to health."