Be very, very careful when venturing in their territory, for if to many spawn you will be completely overwhelmed. If you have a team of tek tier players you could farm the big orange ones and get their venom ( if you can get down and back up alive)
When about three spawn, one will turn into a alpha, ( large and orange) which are the ones that drop the venom. WARNING: When they drop the venom, a bag will drop with the venom inside, it won’t go into your or your tames inventory!!! If ten spawn, a reaper will appear. Keep a light pet with you so they don’t overwhelm you. Light pets will burn them, doing major damage. That’s really all you need to know to fight them!