They’re minuscule, there are millions of them, and one museum manager says they’re massively under-represented. Jack Ashby, who is in charge of the Grant Museum of Zoology in central London, is trying to give dragonfly nymphs, tortoise mites, and sea spiders the attention they deserve, unveiling a “Micrarium” devoted to some of the animal kingdom’s smallest subjects. The back-lit walls of the Micrarium — housed in a former storage room within the larger museum — display 2,323 slides of mini-monsters, some dating back to the 1850s. The Micrarium is open to the public and, like the museum, is free of charge. But don’t all come at once. The room is very small.