Since 1999, Akita has used computers in his recordings, having first acquired a Macintosh to work on art for the Merzbox. Also at this time he began referring to his home studio as "Bedroom, Tokyo". At live performances, Akita has produced noise music from either two laptop computers or combination of a laptop and analog synthesizers/guitar pedals. Reiko A. and Bara left Merzbow during this time, Reiko Azuma now has a solo career. Since 2001, Jenny Akita (nee Kawabata) started being credited for artwork on various releases.  Since 2001, Akita started utilising samples of animal sounds in various releases starting with Frog. Around 2002, Akita became a vegan, he stated how it began:  I started raising four bantams, the little ornamental chickens. With this experience as a start, I gradually started to be concerned and care about chickens and all the barn animals I used to eat without giving it a second thought before. So I started reading books and researching on the internet about Animal Rights and that triggered an awareness of "evil" that human society has done.  During this period, Akita also became a supporter of PETA which is reflected in his animal-themed releases. An example of this is Minazo Vol. 1 and Vol. 2, dedicated to an elephant seal he visited often at the zoo and Bloody Sea, a protest against Japanese whaling. He has also produced several works centered around recordings of his pet chickens (notably Animal Magnetism and Turmeric).  Also in 2002, Akita released Merzbeat, which was seen as a significant departure from his trademark abstract style in that it contains beat-oriented pieces. This has sparked some controversy among fans, though some reviewers pointed out that it sounded very similar to Aqua Necromancer (1998) which features samples of progressive rock drumming. Merzbird (2004) and Merzbuddha (2005) followed in a similar vein with sampled beats combined with Merzbow's signature harsh noise.

Answer this question "why did he choose animal sounds?" by extracting the answer from the text above.
He has also produced several works centered around recordings of his pet chickens (notably Animal Magnetism and Turmeric).