cherry barbs and betta

so, in my 5g micro Asian planted tank i had 3 cherry barbs who hid, buried them self and were never seen, they were with a female betta so i thought they were all right but just shy, after 3 weeks i got worried. then my male betta died and i moved my female into the betta tank. instantly they started darting around happily, who new a girl betta could have so much influence in there behavior!!