The method is that I witnessed in the wood on the day of the storm.

Very slowly the insect veers round from right to left, then from left to right.

Her drill is not a spiral gimlet which will sink itself by a constant rotary motion; it is a bradawl, or rather a trochar, which progresses by little bites, by alternative erosion, first in one direction, then the other.
Before continuing, let me record an accident which is too striking to be passed over.

On various occasions I have found the insect dead in the midst of its task.

The body is in an extraordinary position, which would be laughable if death were not always a serious thing, above all when it comes suddenly, in the midst of labour.
The drill is implanted in the acorn just a little beyond the tip; the work was only commenced.