I had troubles finding them to.
you find them in the desert in area 6.
At your base camp theres is a well you can climb into it and then it drops you right down into area 6.
hope this helps
Any time when a monster is heavily damaged and is about to die if you lay a trap and it goes into it then its captured. But be warned if you capture a monster you can not carve it.
First you will need to weaken the monster the set a trap and throw tranq bomb or use tranq shot (if using bowgun)on the monster. It works best if you throw it on the head
Capturing: When you see the monster start to limp or walk weird. When the monster gets mad when you hit it one time if the monster is sleeping use a pitfall or shocktrap when the monster hits it then you throw 2 traqs at it and you have it.
Catch them using a bugnet.
sure you can use pitfall or other to trap them and you must faster use tran.bomb and some time they will get caught but sometime they will escape!!
Nothing drops Killer Beetles. You catch them in the Flooded Forest with your Bug Net.
Spear Tunas, tailed frog, Ancient Fish and the likes can come from the farm, Fishing upgrade (the one that give you Ballista on your farm. This needs a "net" to use) if you accurate reel in a big catch then there's a chance that these will be one of the fishes.
You don't catch monsters in Monster ranch. You tame them by beating the monster.
Its mouth
Catch them with a net.
They catch pond goldfish.
Where to catch a mars in monster galaxy