If they are good feeders setting a trap for them is a good idea. Get a cage that they could get into and put a rat or mouse inside that can't get out. Put the trap in a nice secure dark place and check on it every couple of hours or each day.
Another one that worked for me although might be frowned upon by others is to tie a piece of cotton to a fresh killed mouse or rat (what ever they eat) and leave it somewhere you think they might turn up. This one needs to be checked hourly, even if you don't find your snake on the other end the direction of the string tells you which direction it was going. also you can put talcom powder etc. along the floor of your shed and look for track marks.
And because jugles are very abboreal, check up in high places, like the corners of your shed rafters etc.
Apart from that just pull your shed apart looking for them. Good luck
