Some American tanks have wicked-looking "forks" welded to their front; this device is called a rhino. Tanks which mount a rhino are called rhino tanks or just rhinos (overloading the term, but the devices never appear in battle except on tanks). Rhinos are used to rip a tank-sided hole in hedgerows. Once the hole is there, infantry and other vehicles can use it normally to traverse the hedgerow. In bocage rhino tanks are very useful.
If you've got Americans in bocage, during setup you should check your tanks to see if you've got any rhinos among them. Select each tank and look at the tank's model name: rhino tanks have "Rhino" in their name. You can also see rhinos as in the screenshot on the battlefield view.