To place an animal push the Place Animals button and make a left click on the map to position it. The animal which you position is the selected animal. The colour of the animal (circle) will turn grey if you clicked. You now can select the height interval. You can see the interval in the z value field on the right of the window. Select the appropriate interval by moving your mousewheel if you use the MS Windows version or use the Page Up/Down keys (this works in all versions) and then click once with the left mousebutton. Once you placed an animal you automatically can place the next animal. If you placed all animals in a scan you can move to the next scan by pressing the + key.
To place the animals more precisly you can either zoom like explained in the map view or you can zoom a certain area. If you press one of the number keys on your keyboard (1-9) the according area it zoomed so that the area is completely visible with the maximum scalefactor. You can go back to scalefactor 1 by pressing the key 0.
Misplaced animals can be deleted by changing into the delete mode by clicking on the Delete Animals button.