It is estimated that the tens of thousands of visitors to the continent each year inadvertently carry with them an average of 9.5 seeds each, often attached to their boots or bags.
Tiap tahun, puluhan ribu pengunjung benua ini diperkirakan tanpa sengaja membawa rata - rata 9,5 benih per orang, sering kali tersangkut pada sepatu bot atau tas mereka.