Rihanna is reportedly a nightmare to work for.

The 25-year-old star rose to fame in 2005 after she was discovered by record label boss Jay-Z.

Since that time, the singer has apparently developed a diva attitude.

A source tells America's Star magazine she is constantly sending people who work for her on wild goose chases to pick up obscure items.

"We're always sent on some errand to the middle of nowhere just to find something trivial, like the 'right' ice bucket or color notepad," a source told America's Star magazine.

Rihanna is currently on her Diamonds World Tour.

The star apparently sent her assistant on a hunt for Mexican food while in Sweden.

"Rihanna wouldn't go onstage until she got carne asada, but by the time he returned - from an hour away - the food was cold. Rihanna threw a fit, like it was his fault!" the source shared.

According to the insider, the singer has never been pleasant with her staff.

Her final break-up with ex-boyfriend Chris Brown earlier this year has reportedly magnified the situation.

"Rihanna has never been easy to work for, but since she and Chris Brown broke up, she's been beyond horrible. She's in a bad mood 24/7 and takes it out on everyone who works for her," the source said, adding, "She's so rude, always snapping at people, and she's a nightmare to be around when she's hung over. I can't even remember the last time she said 'please' or 'thank you.'"