Beyond the potential for unattractive honeydew and stains, though, these aphids are harmless. They don't bite or sting. They also won't live very long in your home as the now-cut Christmas tree ...
However, many baits are ineffective for carpenter ants. We seek to identify attractive pheromones and semiochemicals (message-bearing chemicals) derived from natural food sources (e.g. aphids honeydew ...
If these pests are detected early as a result of regular and careful checks, they can almost always be controlled by mechanical (IPM) means before resorting to using a pesticide for control.
Other ant species herd aphid 'cattle', which they eat and also milk for honeydew, a plant sap excreted by the aphids. They even have their own ‘fences’ to prevent the aphids from straying away.