what's wrong with a bit of senseless violence to a lemming?

they're only going to walk off a cliff.

I would venture a guess they're building them as small as they can. If they could build them smaller, say a one-creature portal, and start bringing critters through, they probably would, so Ockham's razor suggests that they can't build them any smaller.

The other thing to consider is that Earth might not be the first planet they've colonized. They may have a strategy earned from long experience and multiple failures/successes. Perhaps they've learned they need to bring a certain amount of soldiers through at a certain rate to establish a beach head.

- Verveces tui similes pro ientaculo mihi appositi sunt. (I have jerks like you for breakfast.)

 so saith the FDO

TEXANS unite bring the dark overlord to his true home

 aaahh but yes try this one on for size fdo a small gen that consumes it self after one use you know let a general insectoid or a commando insectiod to take control and oversee,corrdate triangle efforts????hhhmmm hhhmmm

TEXANS unite bring the dark overlord to his true home

TEXANS unite bring the dark overlord to his true home

even bigger one to get even more critters through?

G-Man

Nine million terrorists in the world I gotta kill one with smaller feet than my sister. - John McClane

in effect the nature of a failed attemped 1

and the all so favored (plan B) thery into account  2

TEXANS unite bring the dark overlord to his true home

G-Man

Nine million terrorists in the world I gotta kill one with smaller feet than my sister. - John McClane