Formicophilia is a strong desire and lust to be crawled upon by insects in their genitals. There are cases of this fetish where the person also feels pleasure even if the insects are crawling in different parts of his/her body.
Formicophilia
What about it? Formicophilia might be the term you're looking for. Formicophilia is a sexual fetish in which a person enjoys the sensation of small insects or rodents crawling on their skin (or genitals).