Thank you @traveleranna ! This hedgehog is already quite grown up, I think he is more than one year old. Yes, they are very intelligent. I saw one hedgehog crossing the road. He did not just run across the road, like rabbits do, or foxes. He pressed himself to the ground and moved in small dashes. Periodically stops and looks around. He understands the danger. But, this tactics also ruins them. A lot of cautious hedgehogs die under the wheels of cars.