Usually, they are a normal part of development. In fact, 'sexual' behaviors in children are common, especially between about 3 to 6 years old. You may worry that these behaviors are odd, deviant or a sign of sexual victimization.
Seeing what may appear to be 'sexual' behaviors in your young child may be especially distressing. But talking with them about their private parts and sexual development is not always so easy. As a parent, you may be perfectly comfortable talking with your child about the differences between right and wrong.