In Maine they giggle.

gig·gle [gig-uhl] verb, -gled, -gling, noun
verb (used without object)

to laugh in a silly, often high-pitched way, esp. with short,repeated gasps and titters, as from juvenile or ill-concealed amusement or nervous embarrassment.

Synonyms
snicker, snigger, chuckle.

Origin:
1500-10; imit.; cf. D gigelen, G gickeln.