It's funny how he talks about "if the red ants are like normal ants" and all that but... normal ants aren't at all like he thinks. There's no way for a scout or five to tell the rest "hey, i found this huge haul so all of you come right up to take it". Instead, they leave a scent trail on their return trip that there's "some haul", and a few more ants would follow it to go there and check, then those leave new scents on their return so even more come later, and so on... anyway, it'd take multiple roundtrips before any significant amount of them start to gather.