Hello

Please excuse my bad english.

I'm looking for a present for a friend who is gonna to settle in Burundi -the crocodiles' kingdom - soon. I would like something humoristic about crocodiles.

I was wondering if something like a "bird call" for crocodiles exist or somethning that may threaten them, like an ultrasonic whistle (I'm sure that doesn't exist but...)

Thanks for your ideas !