Why Toddlers Can Be So Annoying

One of my friends at school has a 4 (Now 5) year old little sister.  Her 8 year old sister is easily pestered by the fact that the 5 year old constantly asks so many questions whenever I go over to there house.  I remember time she came up on my bunk bed when the girl came over my house.  I think this little girl sets me up for babysitting when I turn 9.