In the 1920s, these were the years when the Miri field began to decline. Exploration was carried out further and further afield. In 1926 an exploratory team had gone as far as Padang Barawa between the Sungai Seria and Sungai Barawa. Not much attention was paid to their findings then, but now with the Miri field declining the old maps and charts were taken out and studied again.
Millions of bat swarms out out of the Deer Cave in order to hunt for insects at dusk, usually about 5pm to 7pm. On some occasions they have been known to fly out at 4pm, usually on darker, cloudy days.