Aphids and ants

Maybe I'm a weirdo, but I think this is cool.

This year, Toronto has a shortage of ladybugs, and a larger-than-usual population of aphids. There are a few colonies of aphids on various plants around the garden (mostly the goldenrods), and just lately the ants have started coming to tend the aphids. Aphids feed on the plant's sap, and excrete sugary "honeydew", which the ants like eating so much they help protect the aphids.

If the aphids were on something I wanted to eat, or on some fabulously expensive plant, I would probably remove them somehow. But since they're on the goldenrod, I'm just enjoying witnessing this symbiotic relationship.

By the way, the shortage of ladybugs this year may be due to a lack of aphids last year, so by leaving my aphids alone hopefully there will be more ladybugs next year.