screaming girls

So I have mentioned I have started babysitting 3 girls after school. So with my 3 that make 6 girls. The oldest is 8, then 2 are 6 (Lydia being one of them), 1 is 5, Karissa is almost 3 and Mikyla is 1. They are so loud I don't know why girls can't talk quietly and why they have to be so loud. Normally I only have the 8 year old and the 5 year old for an hour except Wednesdays (which is today) I have them for 2.5 hours cuz school gets out early. Then the 6 year old that isn't mine I have till about 5 or 5:30 pm. They have so much energy I wish they would share some with me hehe. So yah it's a crazy girl house around here these days.