No, they are not insects. Read below.
Any of more than 40 salamander species (family Salamandridae) prevalent in the southeastern U.S. and Mexico and also found in Asia and Great Britain. Aquatic species are called newts; terrestrial species are called efts. Newts have a long, slender body, and the tail is higher than it is wide. They eat earthworms, insects, snails, and other small animals. Both aquatic and terrestrial species breed in ponds. The three species (genus Triturus) in Britain are sometimes called tritons. The red eft (Notophthalmus viridescens) of eastern North America is bright red during its terrestrial youth, after which it becomes permanently aquatic and dull green.