Waking early started at 7 months

Steph
Our twins just turned 7 months on Tuesday. Starting on Monday they wanted to start their day at 5 instead of 630. Sometimes it's 6 or 7. We haven't changed anything. They go to bed at 730 with whatever they will eat of a bottle and baby food. One is teething but doesn't seem to bothered be it. Does anyone's baby wakes up early starting at 7 months? They eat an 8oz bottle in the morning but this week they are only eating about 6oz which is what they eat the rest of the day