Western Grannom Caddis vs Firebrat

Side-by-side species comparison

Attribute Western Grannom Caddis Firebrat
Scientific Name Brachycentrus occidentalis Thermobia domestica
Order Trichoptera Blattodea
Family Brachycentridae Lepismatidae
Size 9-12 mm 10-15 mm
Habitat Rivers & Streams Indoors
Diet Omnivores Omnivores
Regions Europe Worldwide
Conservation Least Concern Least Concern

Western Grannom Caddis

A widespread European caddisfly forming mass emergences in spring on alkaline rivers. Larvae build four-sided tapering cases and filter-feed in riffles.

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Did You Know?

Spring Grannom hatches on English chalk streams can darken the sky with millions of emerging adults.

Firebrat

A heat-loving relative of the silverfish that thrives at temperatures of 37-39C. Found near furnaces, boilers, and bakeries. One of the most thermophilic household insects.

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Did You Know?

Firebrats seek out the hottest spots in buildings — they have been found living happily inside commercial bread ovens and next to industrial furnaces at nearly 40C.