Assertion or assert may refer to: Assertion (software development), a computer programming technique. assert.h, a header file in the standard library of the C programming language. Assertion definition language, a specification language providing a formal grammar to specify behaviour and interfaces for computer software.
Grass snakes prey mainly on amphibians, especially the common toad and the common frog, although they may also occasionally eat ants and larvae. Captive snakes have been observed taking earthworms offered by hand, but dead prey items are never taken.
Some species prefer hard bottoms (corals), while others prefer soft bottoms (mud or sand) in which to hunt their prey. Most sea snakes feed upon fishes of various sizes and shapes, including eels. Two primitive groups (genera Aipysurus and Emydocephalus) eat only fish eggs; Hydrophis specializes in burrowing eels.