What advantages did the Bugs have over the humans?

Question

What advantages did the Bugs have over humans during the war that made them be so powerful and hard to beat?

Answer 1

Are we talking about the book or the movies? In both book and movie they reproduce extremely fast. In the book it is implied that the humans are winning the majority of naval battles but it is explicitly stated that if a Soldier kills 100 bugs before dying, it is a net win for the bugs because their ground troops are so disposable. In the movie, the humans were significantly less competent so the bugs had an advantage just based on the huge amount of tactical blunders that the humans made.

Answer 2

In the movie series, the bugs seem to have a number of things going for them

Dramatic size advantage

The common "Worker/Warrior" type bugs that we see are at least 10-12 feet in height and with a reach of over 10 foot. In a close combat situation, this gives them a substantial advantage

Dramatic speed advantage

We see the bugs swarming in several scenes. Although it's hard to judge given the background alone, at a gallop they seem to be capable of top speeds of at least 30mph, easily outstripping the average human.

Zerg rush tactics

On many occasions, the troopers appear to be substantially outnumbered by the enemy. The bugs also employ a highly effective (albeit costly) tactic of simply rushing their foes with superior numbers, relying on their lack of concern over casualties to help win the day

Extreme resilience

As Karl notes in the "Know your Bug" segment, the basic arachnid warrior is still combat ready even multiple limbs are shot off. They also seem to be immune from shock, trauma and blood loss

Sheer variety

Bugs come in a wide range of shapes and sizes; Flying "hopper" bugs that give a degree of aerial superiority, acid-spitting "Blister" bugs capable of throwing acid and gigantic "Tanker" bugs that can undermine structures. They even have "Plasma firing" bugs which can be retasked as space-denial/planetary-defence weapons against craft in orbit (when they aren't firing bug spores that can colonise nearby planets without the need for rockets and powered space-travel).

Brains!

The individual bugs might be quite dumb, but they're evidently controlled by a higher intelligence, a so-called "Brain Bug". Although the bug's parameters aren't closely defined, it does appear to be sizeably smarter (and higher value) than a normal arachnid, defended by its own entourage of mini-bugs/warriors and apparently capable of taking control of a human host. This would suggest at least a human level of intellect.