(A picture would go here if I had any decent ones; must wait for sunlight.)
Calliope is a pale beige hooded, and Echo is a medium-dark grey hooded. They are about seven weeks old, although I don't know the exact birthday. They are two of three females in a litter from a rat that was pregnant in the pet store; that rat's owner kept the other female and adopted out these two and the males through the Rattie Ratz rescue group. They're both incredibly well socialized, since she's been handling them from birth. Apparently the mother is also extremely mellow.
They are incredibly cute, and they are going to be so much trouble. While I had them out trying to get pictures this evening, Echo went under the chair (dangerous!) and I couldn't see her well enough to grab her out. While I was trying, Calliope snuck off behind me somewhere. When I turned around to see where she'd gotten off to, Echo abandoned the chair for parts unknown. By the time I spotted her she was halfway up the stairs and moving fast. Oy.
Watching Echo is like watching a particularly active and fearless seven week old rat, which she is. Watching Calliope is like watching film of a normal rat at double or triple speed. They both have metabolisms like nuclear reactors. I've never seen a rat eat this much. Neither of them likes Grape-Nuts, but they are all over everything else they've been handed so far.
Thalia is still soldiering on, but she's probably not in any shape to deal with this level of hyperactivity, so introductions will be waiting until she no longer needs to be introduced. I will be tremendously amused if Clio reacts to these guys the way Niobe did to Clio and Thalia. (Niobe decided that since there were young rats in the cage, she must be their mother.)