Ice sticks to your fingers because of a phenomenon involving intermolecular forces, primarily adhesion and freezing point depression. Here’s a detailed explanation:

1. Adhesion: Adhesion refers to the tendency of one substance (in this case, ice) to stick to another substance (your skin). The surface of ice and skin are both somewhat sticky due to the molecular forces between them. Water molecules on the surface of the ice and the oils and moisture on your skin can form weak bonds (like hydrogen bonds or van der Waals forces), which cause the ice to adhere to your skin.
2. Freezing Point Depression: When you touch ice, the warmth of your fingers slightly melts the outer layer of the ice. This melted water instantly refreezes upon contact with the remaining ice due to the lower temperature of the ice cube. This process is known as freezing point depression, where the addition of impurities (such as skin oils or salts) can lower the freezing point of the water, causing it to freeze faster when touching a colder surface. This quick freeze effectively glues the ice to your finger.
3. Capillary Action: Capillary action can also play a minor role. If there are small crevices between your skin and the ice, water can be drawn into these spaces by capillary forces and then freeze, creating a stronger bond.
4. Wetting Ability: Ice has a relatively high surface energy, which means it tends to “wet” surfaces well. This wetting ability contributes to the adherence of ice to your skin.

Thus, when you try to pick up ice, it can stick to your skin due to a combination of these factors, causing the familiar discomfort we’ve all experienced at one time or another!