Hidden signals are all around us, from hoboglyphs and hand signals, to the leaf which the maid left across our door latch in Thailand. Step one is noticing them, step two is trying to work out what they mean. Moving to San Francisco in January, I noticed something peculiar whilst waiting to cross the street. Beside the drains on the kerb were little rosettes of multicoloured spray-paint, sometimes messy, sometimes neat. They clearly referred to the drains due to their proximity, but who put them there, and why? I went through a few hypothetical scenarios including police checks, construction records, terrible street art or perhaps some illicit gang/drug signals, before the internet stepped in to kill any more fun narratives-
Formed in 2005 following the rapid increase of West Nile Virus in California, this band of pest controllers cycle around San Francisco dispatching sachets of Vectolex into the drains to kill the little biters before they breed. After each drain is treated, the courier sprays a little dot of paint to mark it as completed – this season’s colour is blue. The SFMAC dots are one of those little pieces of infrastructural forensic evidence which helps one feel at home in a city. Not only that, they’re really pretty. I’ve photographed a few and made a wallpaper for you to download below (which is probably unusable).