hi guys, my first post here

my gliders have never been ones to bite, except for the odd nip when i first got them...but in the past couple of days they have started to bite me

they always start off licking my hand like mad, then suddenly bite down so hard they break the skin and wont stop! they cling on tight and just keep biting down

the male generally just nips, but the female bites down hard and wont let go. They've never done this before except for the past 2 days.
so what can cause this excessive licking and biting? my hands are a mess!