In a medium saucepan over low heat, combine the sweetened condensed milk, cocoa powder, and salted butter. Stir continuously until all ingredients are well mixed and start to thicken.
Once your mixture has thickened (about 7 minutes), remove it from heat and allow it to cool slightly. Then, using your hands, shape small amounts of fudge into rounded bodies.
Take each strawberry and gently press it onto one end of your fudge body.
Using roasted peanuts as ears, gently insert them into the sides of each strawberry head. Use colored shaped sprinkles for eyes.
Place your finished mice on a platter and refrigerate them for at least an hour to set completely.