Most of the parasites that feature in Parasites: The Inside Story are worms — trematodes, tapeworms, nematodes, thorny-headed worms, annelids, hookworms, and more. There are a fair number of protists, but otherwise only a few plants, one cnidarian, and one virus make appearances. There's a surprising absence of fungi and insects.

Parasites centres descriptive natural history, covering the life cycle and ecology of each parasite, which usually involves one or more intermediate hosts.

"The fluke Dicrocoelium dendriticum is a parasite of many species of mammals in North America and Asia. It uses land snails and ants as intermediate hosts. Once an egg passes out of the definitive host in the feces and is eaten by a snail, it hatches as a miracidium that eventually transforms into thousands of cercariae. As the cercariae exit, they irritate the snail's mantle cavity, stimulating it to produce extra mucus that forms into balls of slime packed with the parasite. It turns out that the slime balls are a tasty treat for carpenter and other ants. Once inside an ant, some of the parasites move to the abdomen and thorax while others encyst in the brain, turning it into a nightly automaton. When the temperature goes down in the evening, the ant climbs up a piece of grass and holds on at the very top until morning. If it survives, the ant returns to its nest and goes about its normal activities until the next evening when it climbs back up a blade of grass. This behavior repeats every night until an unsuspecting deer or other mammal happens to chomp on that blade of grass, allowing the worm to infect its definitive host."

But there's a lot of broader material: the effects on human and livestock health; the scientific work ("The location of the trapping grid was 1,000 feet up a mountain"); larger-scale ecology and taxonomy (for example South American diversity); and assessments of biodiversity and the threat of climate change. There is, however, no attempt at theory, either ecological or evolutionary.

There are sixteen pages of colour photographs and ten pages of cartoons depicting parasite life cycles — the latter look like they may have come from a children's book by the same authors, Parasites: The Inside Scoop. Somewhat mismatched with that, there's also a thirty page bibliography and an eighteen page appendix with more systematic information on the parasites discussed, along with line drawings.

I found The Inside Story an easy and engaging read, but suspect it lacks the punch needed to command a wide general audience.

June 2026

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- Judy Diamond - Kea, Bird of Paradox: The Evolution and Behavior of a New Zealand Parrot
- books published by Princeton University Press