yes, rats have very poor eyesight and if your hand smells like food, rats will think it is food …. so it was an accident. Also, in case you are unaware, you should never feed rats through the cage bars as this will teach them to bite everything that comes through the bars - including little fingers
Sounds like the baby is afraid …. and no wonder, he has just lost his mama and all of his siblings except one, is in a scary place with different smells, different noises, a different cage ….. and he is just a frightened little baby missing his mama and his home ……
and it has only been two days - being willing to come out and take something from you is pretty good imo …………………. also just like people rats have different personalities and some rats are more extroverted then others but that does not make more introverted rats less wonderful companions
You need to give him time to adjust, and he should be fine
It is great that you are handing them food so they will learn to trust you and learn that you give them good things
How old are the babies?
Are the rats in a huge cage with all sorts of interesting things, in a main room of the house so they can get used to you?
How are you picking them up? Are you scooping them up from underneath using 2 hands or is your hand approaching from above them, like a predator?
Do you have other animals in the home?
Once the babies have time to get used to their new home, you can put on a loose shirt over a tight shirt, put both babies on you between the two shirts, and sit down to watch TV or read for 20 or 30 mins. This will help them to get used to you and your smell while feeling safe.
joinrats.com has a lot of info on socializing rats etc so you may want to check out that site
Babies and young rats are normally very active and like young children, do not like to be held for long as they need to run and climb and play and explore, so having a rats safe play area where they can do these things and also interact with people is important
Hope that you post lots of pics of your sweet boys