Hollowing techniques are a combination of drilling and scooping out materials. This type of secure holding system is essential for hollowing bowls or hollow forms. The larva develops within the grain, hollowing it out while feeding. Hollowing out the logs further increased buoyancy and payload. The drums are normally made by hollowing out logs and stretching antelope skin over them. Their concept involved the hollowing out of a stick of juniper wood. Tubular aluminum is flexible and hollowing, besides less sturdy. The first versions were made by hollowing out sticks of juniper wood. The central and neural spines show early hints of hollowing as a weight-saving measure. Hollowing out the side door beams. He brings his arms up while hollowing out his back. Many are now made of bamboo, which do not require hollowing. Mayorga played drums on the album "The Hollowing" with metal band Crisis in 1996. This was ascribed to age and the natural hollowing of the trunk with time. This will often result in a hollowing if it persists for long periods of time.