When female dogs are in heat, do they tend to get aggressive towards other dogs?

I have an 8 month old boxer puppy, and and a 3 year old pit bull. They LOVE each other, and very rarely get into fights. They both have good temperaments and are rarely aggressive to each other. Recently, my puppy has been very aggressively (i'm not really sure what word to put..) snipping at my pit bull. We're thinking that maybe the puppy is in heat right now (she is not spayed). So do female dogs sometimes get nasty with other female dogs when they're in heat? Her behavior is really starting to concern me