Me and my daughter are getting bitten!

Me & my daughter live in a clean and tidy house.
But we keep being bitten by something whilst asleep in our room!
Mine have bin very painfull and swollen up very badly but my daughter
Hasnt seemed bothered. We do live with my sister who's room is a pig sty! But we dont go in there. What could it be that's biting us? And how could we prevent it?
Thanks x

Assuming the windows have secure screens and it's while you're asleep, it's likely bedbugs. Take everything off the bed and wash it in warm soapy water.

If there are pets around, it could be fleas also but they will be everywhere, not just in the bed.

I don't know much about bugs and whatnot, but I remember that going on back in Vietnam. We had loads of bugs and mosquitoes biting or flying around at night. What we did, was we bought nets to surround our sleeping area. The nets were small enough to the point where bugs and all that stuff can't get in. We put up nets around everybody every night and it seemed to help. Check around your house as well. You might have some nest of bugs that come out at night. I hope this helped.

Everyday I spray lavender water on our bedsheets because the smell is heavenly and calming, and it helps my husband wind down before sleeping. My daughter just told me that it has repellent qualities. I looked it up, and sure enough, it repels bed bugs.

http://theherbgardener.blogspot.com/2009/06/quick-lavender-bed-bug-spray-for-you.html
http://www.ehow.com/how_6746973_rid-bed-bugs-homemade-formulas.html

A few years ago my husband told me that one thing you can do to avoid bedbugs is air out the bed on a regular basis. That was ALL I needed to hear to stop making the bed and leave the sheets pulled back during the day. We make our bed when we're about to get into it, and we keep our dogs out of our room. Keeping them from sleeping with our son is a losing battle...