OK to feed black oil sunflower seeds in the hulls to my 12wk olds? I haven't started feeding grit yet, they get grower crumbles and treats are soft - yogurt with cooked oatmeal, clover and greens from the yard with the occasional handful of crimped oats to scratch for. If it is okay to feed the sunflower seeds, should I start feeding chick grit too? Is parakeet gravel an acceptable form of grit? They are growing like weeds!