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.
Grass snakes are excellent swimmers. Grass snakes are non-venomous, grey/green in colour (sometimes with black spots) and a yellow/cream/orange band around the neck. A black line runs from the eye to the mouth and the underside is usually white or pale yellow with a chequered effect.