Answer:
The slugs melted because it lost much water and got dehydrated.
Step-by-step explanation:
Slugs- This is a terrestrial mollusc which lacks shell and secretes mucus for its protection. The mucus also helps it move around. It is tough-skinned and is also considered a pest for plants. You can find them in cool, dark and moist spots such as the base of plants or very old pots.
Slugs are sensitive to "salt." If you mix slug with salt, it can interrupt its normal life span by creating a salt-water solution. Remember that slugs are normally made of mucus, which is made up of water. High concentration of salt can draw water out of a body's sell, thus causing it to dehydrate and even die. This mechanism is called "osmosis."
Osmosis- This is the movement of water or other solvent molecules through a semi-permeable membrane, from a region of low solute concentration to a region of high solute concentration.
The potato chip bag in the situation above served as the container of the slugs. Remember that potatoes are salty, and the chip bag definitely has salt residues in this case. This is the reason why placing the slugs in it for a long period of time can dehydrate them. No wonder they turned into slime!