Wikipedia on Hedgehogs.

"In 2006, McDonald's changed the design of their McFlurry containers to be more hedgehog-friendly. Previously, hedgehogs would get their heads stuck in the container as they tried to lick the remaining food from inside the cup. Then, being unable to get out, they would starve to death. Domesticated hedgehogs display this behavior by getting their head stuck in tubes (commonly, lavatory paper tubes) and walking around with the tube on their head. Hedgehog owners often refer to this as "tubing" and promote the behavior by supplying clean tubes. Most owners are considerate enough, however, to cut the tubes lengthwise so as to prevent the hedgehog from remaining trapped against their will. Curiously though, some will still knowingly get themselves stuck for a few hours."
"Observe Everything. Always think for yourself. Never let other people make important decisions for you." — from Bad News by Edward St. Aubyn