I find it fascinating that no one else mentioned how our astrological signs affect our personalities. Granted, I know many people dismiss it, but usually w/o much understanding, and they usu. say that if their sun sign personality doesn't fit, then it doesn't work. You have to look at the complete profile b4 you dismiss it, and usu. when people see their complete profile, they find that it fits. Mind you, I'm extremely scientific as well - I used to be a physics major. This is in part why I DO support the concept- but I won't get into all that here.
You didn't say which child is which, but I'm guessing your older child is the more challenging one because if I guessed right by you saying he's "almost 5" - then that means he is an Aries Horse. Of course I don't know his moon or rising sign, but Arians demand being in charge & are very bad at following others. Equally, the Horse (Chinese astrology) needs plenty of room to roam, and want freedom & independence, while at the same time wanting love & intimacy, which leads them to often feel trapped. Likely to be perpetually on the go, witty & spirited. Brillant but rash, dauntless and impatient.
Your 3-yr old is either a Sheep if born early in Jan. 2004 or a Monkey if the rest of the year. If a sheep, he enjoys peace & being artistic & daydreaming, and needs lots of love. If a Monkey, he'll be more of.. a monkey! The original party animal, charming, energetic, and very accident prone. My little brother (now 27) is a Monkey & he was very much like this, but also a little doll. He got totally spoiled b/c of how sweet he was. (But very cunning!)
Anyhow, all of this is overridden by their Sun sign (outward nature), Moon sign (inward nature) & Rising Sign (strong add'tl influence). I'm curious - am i even close?
If you wish, you can send me their birthdays (incl. time of day) & I can tell you 3 of their signs (sun, moon & chinese yr). I can't do Rising b/c you have to be able to do complete charts to get & I don't know how to do that (yet). I can send you links to free text about each & you can see for yourself.
btw, I'm a Gemini sun, Leo Moon, Saggitarius rising, Wood Rabbit.
Peace!