X-ray images aren't only used with human subjects but also, for example, on insects and flowers. In 2003, a team of researchers at Argonne National Laboratory used X-ray imagery to find, for the first time, that insects, although they do not have lungs, do not necessarily breathe completely passively, as had been believed previously. Many insects rapidly compress and expand their trachea, head, and thorax in order to force air in and out of their bodies. One difference between X-raying a human and an insect is that if a medical X-ray machine was used on an insect, virtually 100% of the rays would pass through its body, and there would be no contrast in the image produced. Less penetrating X-rays of lower energies have to be used. For comparison, the typical human body mass is about 70 kg, whereas a typical ant is about 10 mg. Estimate the ratio of the thicknesses of tissue that must be penetrated by X-rays in each case compared to the other.