They've been home 22 hours....

And already it is very evident to me that the research about siblings is accurate:

The Science of Siblings

Laurie Kramer, professor of applied family studies at the University of Illinois at Urbana-Champaign, has found that, on average, sibs between 3 and 7 years old engage in some kind of conflict 3.5 times an hour. Kids in the 2-to-4 age group top out at 6.3--or more than one clash every 10 minutes, according to a Canadian study. "Getting along with a sister or brother," Kramer says dryly, "can be a frustrating experience."

I feel so much better knowing that my kids are statistically above average. I'd say they are fighting an average of 10 instances per hour since returning from vacation. And right about now, I'd like to send them back to from where they returned.

Is it bedtime yet?