The Perils of Home Automation: Invasion of the Birds

Once upon a time in 2009, we had some pet cats. On occasion, we would venture off on some adventure. Being good cat owners, we wanted to make sure our furry feline friends stayed well fed, and out of trouble.

To that end, I constructed an automatic cat food dispenser. It was constructed out of a discard water pipe end, a rotisserie motor, a round hair brush, and a bowling ball. And given a coat of grey paint.

The cat food would be put in the top area of the dispenser, waiting for the rotisserie motor to slowly churn the food onto a waiting plate below. The dropping cat food would make a plinking noise on the glass plate, letting our cats know that food had arrived.

However, after a while, the cats got lazy, and perhaps overfed, and were not eating the food right away. So the neighborhood birds moved in, to help with the cat food.

I viewed this as a problem, and decided a bit of home automation may solve the invasion of the magpies. I added a motion detector on our pergola slightly away from the house (and the cat food feeder), pointed downward. When triggered, the motion detector would activate the sprinklers near the house. This area had mint and various flowers growing in it. It worked to scare the birds away.

A few weeks later, we headed out of town. Before we left town, we had friends over for a backyard barbecue, and they remarked about some of the mind growing in our backyard, near the patio.

Before we left town, we had told them to stop by and grab a patch of mint as a starter. Now that we were out of town, they were out on a bike ride. As they were in the area, they decided to stop by and grab the mint.

They wheeled their bikes into the back yard, and proceeded to cut out a patch of mint. However, the mint they selected was directly below the motion detector, so their efforts were complicated by the sprinklers turning on several times. Eventually they got their mint starter.

Later that day, a hundred miles away, I checked the automation logging and saw that the backyard bird invasion had begun. The birds had been furiously setting off of the motion detection for about 25 minutes.

Only later did the truth of the tale become evident.