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.