I can't believe I forgot just for a moment how amazing and crazy Tsutomu Nihei's works are... Blame! was and will always be my most favourite and cherished manga but really all of his work is truly not from this world!
Been keeping a jumper in a small container for a week now, he's starving and I introduced a small black garden ant now, he stared at her cautiously observing every movement she made and acted accordingly, after about 8-10 min he gave up and is now avoiding her as non-potential prey. He's starving but he still won't risk attacking an ant, that's judgement over instinct and a great sign of these spiders' intelligence.