Is vanilla ice cream safe for mice to eat?

No.

Mice are lactose intolerant, meaning that they lack the enzyme lactase, which is needed to digest the lactose in milk and dairy products. Lactose intolerance can cause gas, bloating, and diarrhea in mice. In severe cases, it can even lead to dehydration and death.

Vanilla ice cream is made from milk, sugar, cream, and flavorings. It is high in fat and sugar, which can also be unhealthy for mice.

Giving vanilla ice cream to mice is not a good idea. It is not only unhealthy for them, but it can also be dangerous.