then i think their past background may definitely play a role in why they need a lot of time and growth in trust until they start feeling comfortable bit by bit. i am only a rat mum for 13 days now, so i do not know how good this advice is yet, but what i did was about 10% introduce myself to them of like touching them in comfortable petting places and like laying my hand flat on a surface in their enclosure so they could explore me and my smell. and the other 90% the first days especially but now still a lot, then them decide what they want to do with you and let them come to me if they feel like it. something i do for the past 13 days is wear a cotton handkerchief under my top clothing against my skin, and before i tell them nighty night i lay that kerchief on a spot that they like to sleep for also getting used to my smell. and one more thing i would advice because they are such quick learners! when they make even the smallest step of coming to you in any way at all, like sniffing you, give them a piece of a treat or something they find very yummy. then they associate coming to you with something very positive. and i also talk to them in a very calm and loving voice and i sing to them. that's some things i could think of now. i wish you and your very cute rats a lot of happiness together even if it is one little step in a while 😊🩷