Ah Bless! The wee hedgehogs being looked after in a refuge all over the long cold Winter, were so well fed, they were far too fat to curl up into balls to protect themselves from predators.
What do you do with clinically obese hedgehogs? You put them on a diet of course. They are now svelte enough to do what hedgehogs should be able to do. They will be safe to let out into the big bad wildlife world, hopefully, where there is lots of countryside between them and roads.