Hedgehog

We left an old rolled up carpet outside on the garden path before Christmas and intended to have the council remove it.   We had a hedgehog coming in under the gate most nights for a rummage round the bins.  We think it must have crawled inside the carpet to hibernate because we didnt see it for a while and our two lurchers kept trying to see into the carpet and whining near one end of it each time they were outdoors. We have  left the carpet where it is so as not to disturb the hedgehog if he is actually in there.  We were wondering when will it be  safe  to have the carpet removed, how will we know if the animal has woken up and gone. It's not possible to see inside the carpet without unrolling it all.