Just take into consideration their food needs. and warn ur bro when they bite they tend to latch on.
Ive raised plenty and been bitten too many times
Rats are great pets they usually only live to about 3 but my best one was 8 when he had to be put down with a tumor. and he was HUGE.
PLUS they are great neck warmers, i have waist length hair, a pro and con, pro: rats love to hide, con: rats get tangled easily
you can also get harness's for them
Ferrets are good and funny as hell too.
again they can be walked on a leash and harness.
Mice are ok for young kids but are too small to be much amusement for me lol plus they are more fragile. one of my mice was being held by my little sister once and it ran up her sleeve and she automatically tightened her elbow (brough her fist to her shoulder bending the elbow) and squashed my baby and killed it :(
Rodents (ferrets rats mice gerbils etc) need their bedding changed daily-every second day due to the smell that will begin to emerge otherwise.
Blue tongue or pink tongue (same animal different type)
are a great pet, smooth skin like the snakes they bite like any lizard but are very....easy going.
we have hand raised a litter and eventually had them trained to eat via tweezers, a ball of mince meat coated in egg mmmm
but let us all know how u go :)