As per above source:

Most people are unaware of the maggots presence, although a small number of patients claim that they can feel the maggots moving but only describe this as a tickling sensation

Some other good FAQs:

Will Maggots bury into healthy tissue?
The maggots used in wound management will not attack or bury into healthy tissue, they only remove dead tissue.

Will the maggots multiply in my wound?
Only adult flies can lay eggs, so the maggots cannot reproduce or multiply within the wound.

Where do the maggots come from? Maggots are produced in a special unit by highly trained staff at Biomonde, a company with many years of experience in wound management.