An ant no larger than a grain of rice is drawing the attention of conservationists on some of the world's most fragile islands. The Argentine ant (Linepithema humile), introduced to many regions through human activity, has spread well beyond its native range over the past century.

An ant no larger than a grain of rice is drawing the attention of conservationists on some of the world's most fragile islands. The Argentine ant (Linepithema humile), introduced…

Long before most Californians noticed them marching across kitchen counters, Argentine ants had already transformed the state’s ecosystems. Introduced from South America in the…