If you are still doing it, have you experienced traveling with your little ones but they happen to have an unstoppable call of nature? (shrewdmommy.com)
We are sorry, but we will not accept phone calls of this nature if you do not have an approved adoption application on file. (kentuckianapugs.com)
Then God considered the function of bladders and decided seniors would have additional calls of nature, requiring more trips to the bathroom, thus providing more exercise. (justarsenal.com)