English crickets are picky crickets. Field crickets such as the one shown here like to bask in the sun, and their favorite habitat is the close-cropped grass of a sheep pasture. Wartbiter crickets, on the other hand, prefer fields grazed by cows, which leave enough long grass for wartbiters to hide in. Like sheep and cows, the two crickets don’t mix--but in the past few decades, as both cows and sheep have become less common in the English countryside and pastures have become overgrown, both types of cricket have suffered. In 1991, with only 100 field crickets remaining in a single population in West Sussex, researchers at the London Zoo embarked on the sort of captive breeding program usually reserved for higher-profile or furrier animals. The field cricket is a lovely, beautiful squat cricket, explains London Zoo invertebrate specialist Paul Pearce-Kelly, and very interesting because it makes burrows. It’s really quite sweet, actually. In the summer of 1992 Pearce-Kelly and his colleagues began releasing captive-bred field crickets, and this past year they released 1,500 more. The program, they report, has been a success: there are now seven populations of field crickets instead of one--and the species has been pulled back from the brink of extinction. The researchers have also started releasing captive-bred wartbiters, with comparable results.