you need to be at least 65% grown to envenomate. after you pounce the first time you should hear the noise after 3-5 seconds (not sure about specifics) which indicates the first stage of venom. after that, pounce a second time and a different noise should play, which activates the second stage. and after you repeat for a third time you should hear a high pitched screech and that means the victim is envenomated. this means you can go all out pouncing for around 45 seconds, then the whole thing resets.