Crocodile target trained

I have been watching a series on TV about Chester Zoo. In one episode they had a crocodile who needed a blood test. The crocodile had been target trained and was also used to having her tail lifted and stroked as this is the area where the blood would be taken. The crocodile would nudge the target and keepers at the head end were feeding her while a keeper at the tail end was in the water and lifting the tail. Then the vet arrived to take the blood which was all done successfully. The crocodile was continually nudging and noshing while the vet was sticking the needle in.

Jane