Unless attacked by a conspecific, the beetle separates and forms a food ball on the top of the dung pile.
When the formation and rolling of the food ball were started by a male, he violently rejects other males but accepts a female and paired rolling begins.
The following regime was then used for about 1 month to condition the test animals to accept "food balls":
But in addition, diced fish or shrimp was incorporated into "food balls" gelled with carboxymethylcellulose, compressed onto the end of a monofilament line, and presented as described above.
When bass in the laboratory were given food balls
, those impregnated with shrimp extract were swallowed, but those without flavor were ejected from the mouth after the bass decided that they weren't tasty enough.
In some of their experiments, the scientists fed bass goldfish and artificial food balls made of gels of varying compositions.
In lab tests where the artificial food balls didn't contain any feeding stimulants such as pureed shrimp or minced fish, 8 bass spit out the ball within 3 seconds.