Board Thread:Questions and Answers/@comment-98.254.36.213-20140524130321/@comment-28320688-20160509182356

Here are the reasons from the game (With proof):

They are rubbery (BMC trailer),

Annoyingly speaky (BMC trailer again),

Threatening the social fabrics of monkey society (BMC trailer,),

They tickle monkeys to death (One of the bloonarius messenges in BMC.)

They are used as weapons (BMC and BTDB)

They destroy all technology and advantages the monkeys have above them (BMC and BTD5)

For that last point, i think Ninja Kiwi is trying to give a messange. Imagine the bloons as animals and monkeys as humans. Exactly real life. Animals are doing nothing, and we humans kill them and destroy their habitats. Animals try to fight back, but we always win.Bloons in BMC live in nature, and so do animals. But we come, destroy thier homes and build cites over it, Just like BMC. So that is a very strong and secret messange in a game.

List carry on:

They spy (BMC)

They bring fear (BTD5, BTD4, BTD3, BTDB, BMC)

They steal power, trade and industry (BSM2, BMC)

They steal objects (BSM2, Possibly BTDB)

They try to counter everything (Since BTD1)

They make the original bloons monkey rage since he can't pop enough bloons to win (Original bloons series)

They try to go somewhere, but they dont have a passport or flying license or pass or something, and the monkeys pop them for breaking the monkey law, so then the bloons call backup (Just inferred this from BTD5)

They possible may be a sport, as said by 114.76.24.53 (BTDB, BTD5)

They may be popped as they contain useful materials the monkeys use (Where do you think you get money from, and what about the shacks?) (BTD5, BMC)

They make good targets to train, so later monkeys can fight with other monkeys later (BMC, BTDB, BTD5)

They are breaking the laws of physics, since road spikes pop them even though the bloons float. Who gave the bloons oxygen and not heluim? Maybe to make them alive? (Just thought this one up ._.)

So there is your list.