Ariana Grande touches fans as she performs during the MuchMusic Video Awards
Ariana Grande touches fans as she performs during the MuchMusic Video Awards (MMVA) in Toronto, June 15, 2014. REUTERS/Fred Thornhill REUTERS/Fred Thornhill

Every celebrity participated in the ongoing ALS Ice Bucket Challenge with complete enthusiasm and dedication, but there are a couple of celebrities who are not very keen on it for various reasons. "Baywatch" babe, Pamela Anderson and "Problem" singer, Ariana Grande are the two celebrities who did not participate in the challenge in a way everyone else did.

In Pamela Anderson's opinion, though she has participated in various charities earlier, she could not "bring herself" to do the latest ALS Ice Bucket Challenge. She, instead, wants to challenge the ALS foundation to stop using animals for the purpose of testing medicines. The 47-year-old animal rights activist took to Twitter to express her thoughts on how the innocent animals are used mercilessly for testing various drugs for the ALS disease.

"Recent experiments funded by the ALS Association, mice had holes drilled into their skulls, were inflicted with crippling illnesses, and were forced to run on an inclined treadmill until they collapsed from exhaustion. Monkeys had chemicals injected into their brains and backs and were later killed and dissected," writes Pamela on Facebook and Twitter.

The actress also mentioned about the FDA statistics which show that "92 out of 100 drugs that succeed in animal trials fail when used on humans." She even urged people to find and support charities that do not harm animals at all in their research and asked the scientists to use "sophisticated non-animal testing methods-including in vitro methods" to find a cure to Lou Gehrig's disease.

For Ariana Grande, the reason for not participating in the ALS Ice Bucket challenge was completely different. The 21-year-old revealed to MTV that she has donated money to the cause of Lou Gehrig's disease research but did not find it necessary to upload a video of her doing the challenge and waste water when millions of people are suffering from the crisis of lack of water.

"I made a donation! Do I have to waste water during a drought and dump a bucket of ice on my head if I actually donated?," wrote Ariana during her @MTV Twitter Takeover on Friday.