Hey hun, Im expecting identical twin boys, so i know exactly where you are coming from. Like you I find that one is alot more active than the other, and I have been to hosp several times to monitor their heartbeats, as Im not sure if i can always feel both of them moving. Its really hard to know who's who with twins sometimes, and i've ddiscovered that when i've thought i couldnt feel one, its usually because he's got his feet right next to the others, and in actual fact i can feel both moving but not realised it! If you have any worries at all, pop into hosp and get checked out. Dont hesitate. They are always very cautious with twins and will just pop you on a monitor and get you checked out. Every time i've been I always feel like theyre going to say "not you again, go home you paranoid woman" but they dont! They always take it seriously and theyre really nice about it. There is a twins and multiples section on this site also, always worth checking out. All the best, and if you have any questions at all, feel free to PM me. x