I think maybe they do it via low frequency vibration, or a type of infrasound which manipulates their electro magnetic field.

It's already a well known phenonimon within the sasquatch investigation field that they seem to be able to alter a humans energy field, by making you feel sick, disoriented or both. It's thought by most researchers they do this by emmiting infrasound directed at an individual's electro magnetic field.

The cloaking phenonimon is not widely recognized or accepted among researchers, mostly because it's not known about by many.