Highly resistant electrical damage. Leaves behind a trail of Slime.
Occasionally lays Snail Eggs, which will hatch a short while later, spawning a number of Ickslugs. The eggs can be destroyed before they hatch by the use of melee attacks, grenades, fire, etc, preventing any Ickslugs from spawning. However, shots from missile weapons will merely fly past the eggs harmlessly.
Since Ickslugs ignore AV and are Swarmers, a large group of them can be a very serious threat. Snailmothers should therefore be eliminated as soon as reasonably possible, to minimize the number of Ickslugs they are able spawn.