So I got two 5-month-old rats (both males and I'm assuming brothers) how do I get them to trust me? I've currently been doing little things like letting them sniff me and hand feeding them treats. They are incredibly skittish and don't like if I try to pet them. Also - one of them keeps grabbing my finger (or anywhere he can) with his teeth, it's not hard but it's firm and sometimes hurts a little.
Stop trying to pet them. Back up and let them come to you in their own time - could be weeks or months, but let them choose it. Stop by and talk to them without touching, drop off food and leave, hang out and let the choose to sniff your hand. Teach them that you won’t pressure them to go beyond their comfort zone and they’ll be more willing to explore and investigate you.