You have reminded me of of my research days. It was very common in the forest where I worked for my Ph. D.
Dr. Gurcharan Singh
Retired Associate Professor
SGTB Khalsa College, University of Delhi, Delhi-110007
Res: 932 Anand Kunj, Vikas Puri, New Delhi-110018.
Phone: 011-25518297 Mob: 9810359089http://people.du.ac.in/~singhg45/