by KYW's Karin Phillips

The Philadelphia Zoo's three tiger cubs are growing fast and are now learning behaviors to help trainers take care of them easier (see previous story).  

Koosaka, Changbai, and Terney are about four months old now and averaging about 40 pounds each. They are eating their collective 15 pounds of red meat a day, playing, and scampering around their exhibit at the Zoo's Big Cat Falls. Now, it's time to train the cubs so the Zoo's keepers can take care of them properly. Permanent keeper Tara Brody:

"They're starting to learn some basic behaviors that will help us when they're bigger to take care of them, like sit and lay down, get on scales. We're going to have to vaccinate them pretty soon."