WATCH: Toronto giant panda cubs start teething at 12 weeks

Every week there’s a growth spurt for Toronto’s giant panda cubs but at 12 weeks it’s all about the teeth.

Toronto Zoo officials say the teething process has begun as the twins are now over 3.5 kilograms.

The cubs are still spending time with their mother Er Shun in the maternity den and are still not available for public viewing.