Snark Nest

The player can obtain an egg sack containing 5 Snarks which can be used as weapons. While held, Snarks have an unlimited lifespan, but still show aggressive tendencies (as two comical idle animations show one animation with the Snark struggling in Gordon's hand, and the other with it snapping at Gordon as he teases it with his finger). Once thrown, the Snark's twenty-second "attack mode" begins, and it will immediately charge at the nearest living thing and attack it. If there is nothing for them to attack, they will turn around and attack Gordon instead, which is why the player should always be sure to throw them from a higher vantage point, or only use them if there are enemies to throw the Snarks at. The Snarks will remain in this frenzy until they fall apart and die, which clearly originated as an emergency defense mechanism to protect their nests in the wild. Half-Life (c) Valve