> Who's ethics?

Mine, I am not speaking for some higher power.

> Generally, a way not to be an ass, is to avoid taking life unecessarily.

And here is the problem with your argument, this art form takes lives necessarily. So the question is, if we are better off without a few ant colonies or without an entire art form.

Perhaps one day killing will be seen as "getting one's hands dirty" and unecessarily organic in an otherwise square, cold, sterile, sharply edged world. Killing will not stop for morals but rather for reasons of seperation. Meals will be perfectly produced homogenous mixtures of 3d printed amino acids, vitamins, and sacchatides. Yeah.. I dont have much faith in the ability for people to trade pleasures for lives.

You can buy bug spray in the supermarket, because chemically torturing and murdering flies is acceptable. Where is the outrage?

Nobody is doing art exhibits with bug spray nor are they running around nature spraying nests for no good reason. If pouring aluminum was done for science in a limited number of times then that's acceptable, but doing it just to produce cheap artifacts of dubious artistic value is mildly obscene.