As millions of households in North America are faced with devastating natural disasters, a new flying pest arrived at my small porch.

Following an extreme heatwave in Mountain View, CA, these winged insects started appearing along a shaded area in my porch in the early morning. They are 3/4" long, completely black with only the tips of their legs semi-transparent white. Their wings are black and opaque, and they hold them close to their bodies. Their V-shaped antennae don't match neither termites nor ants. By 11am, when the temperature rise, they are off.

Can you help identify these?