So today I was doing my morning check on the plants and noticed some small winged creatures black in color. I assume they were aphids. Killed 1-3 per plant. I only saw mature, winged ones. I live nearly at the top of my building, some 30 meters up from the ground level. I've quickly skimmed/checked other plants on my terrace and didn't spot a single aphid on them. So not really sure where they came from, perhaps from my neighbors. My question is, should I worry about this? I'd rather not spray anything toxic on my plants if I can hand-manage this for now. Thanks, cheers!