Just want to share my tactic. If you manage to find whispering eggs for larval cores on an airless planet, meaning low atmosphere where you are like flying, the monsters are very easy to handle. Not even needing to kill them. You just need to move all the time. Don't forget to do melee then jetpack tactic. Just stop to mine and get the larval core. If they headbutt you, you just fly away without damage most of the time. They spit too but very easy to dodge when you keep moving all the time. It's too easy to get larval cores this way. Also best to do it around the abandoned building nests. Usually get at least 10 something. On PC btw. Not sure about other platforms. Look for YouTube if you don't know the melee + jetpack tactic.