Yes, you’re son is correct. These are Aphids, but the good news is, many of them (the black and the tan ones) appear to have been parasitized – which means they are dieing due to a tiny (stingless) parasitic wasp that is developing inside each of them. This is nature at its most interesting and amazing! You do not need to do anything, except allow the incubating wasps to develop so they can emerge from the aphid “mummies” and lay their eggs in more aphids. However, we also see ants in this photo and they should definately be controlled because they will try to keep the parasitic wasps away. They do this because they feed on the aphid excrement (its very sugary) and are trying to preserve their food source. Ants are best controlled with baits. We’ve included links with more info and strongly advise that you do not use pesticidal sprays to control ants, especially those you find on your plants. These pesticidal sprays will kill the natural enemies of Aphids (which are numerous and include the parasitic wasps) and could do damage to your plants.
http://www.ipm.ucdavis.edu/PMG/invertebrates/links.ants.html
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74140.html
http://www.ipm.ucdavis.edu/PMG/NE/index.html
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