Peanuts

• Peanuts have a mold that squirrels find toxic, however this is eliminated when they are roasted. They lack calcium and other nutrients, so they shouldn't constitute the main part of their diet -- and don't give them salted ones.
  
  

Cashews

• Keep cashew nuts to a minimum, as they lack minerals, in particular calcium. Diets that are low in calcium can result in brittle bones. Avoid salted cashews at all costs, as they contain too much salt for a squirrel which can increase their heart rate and can lead to premature death.
  
  

Sunflower Seeds

• While squirrels can eat sunflower seeds, they shouldn't eat too many of them, as they provide very little in terms of nutrition.
  
  

Pine Nuts

• Pine nuts have little to offer in terms of nutrition, although squirrels eat them if they are offered. Only feed them pine nuts with a variety of other foods.