alert the spiders

'Alert the spiders' is a rural colloquialism from northern California where I grew up in the '60's. I heard it from my parents and grandparents (California, New Mexico, Nevada and Iowa) all my life. It referred to rural mail routes out in the country away from town. Often spiders would get into the mailboxes and spin webs. Sometimes we would sweep them out with a broom if they got too close to the front, but often we would just leave them alone. When important letters or small packages were being sent, we would receive a phone call from the sender who would say "Alert the spiders!" and we would know to watch for the mailman who would place the treasure in the mailbox, disturbing the spiders who might get crushed... if we hadn't 'alerted' them.