Jessica Alba went ''crazy'' during her pregnancy.

The 37-year-old actress welcomed her son Hayes into the world eight months ago, and has said that changes in her blood sugar levels whilst she was pregnant caused her to ''lose [her] mind a little bit'' and ''grunt like an animal''.

The 'Sin City: A Dame To Kill For' star - who also has Honor, 10, and Haven, seven, with her husband Cash Warren - said: ''On a daily basis, when the blood sugar got low, I would go crazy.

''I didn't mean to. I would just lose my mind a little bit. I would just break out into a sweat and I would get thirsty and I couldn't find words.

''I would just grunt, like an animal. Good times. Good times, being pregnant.''

Jessica also revealed that just like all new parents, she had embarrassing moments and mishaps when her children were young, including one particularly gross incident with one of her daughters.

Speaking about her most embarrassing mom moment, she said: ''I have made the mistake of not having diapers, and it's always at the worst time. Probably walking out of a restaurant with a swaddle blanket around my kid because I didn't have any more diapers and she pooped through three outfits and on me. Really fun.''

But the 'Fantastic Four' actress understands parenting isn't always ''easy'', and says she wants to teach her brood to put in ''a great deal of effort'' in order to achieve their dreams.

She told People magazine: ''Things aren't gonna always come easy in life and anything that's worth having, you have to work for. I wasn't naturally really good at anything, so it always took a great deal of effort to accomplish anything for me.''