Why Does My Cat Prefer Dirty Water That's Been Sitting Around to Fresh Tap Water?

Posted by Jennifer Copley May 6, 2009

Cats often perplex their owners by turning their noses up at a freshly filled bowl of water but drinking happily from muddy puddles, glasses of water that have been sitting around overnight, or even the toilet. Why do cats do this?

Cats have a far better sense of smell than people, which affects their sense of taste as well, and some cats find the chlorine in tap water unpleasant. Standing water, such as that in the toilet bowl, is free of chlorine because the chlorine dissipates over time. And of course rainwater in outdoor puddles is free of chlorine to begin with.

The chlorine in tap water is also the most common cause of brown leaf tips on certain houseplants (also known as tip burn), though this can occur for other reasons as well. Thus, for some pets and plants, it may be necessary to leave water standing overnight before providing it.

For more information on cat behaviour and cat care, see:

• Why Does My Cat Do That?
• What Should I Feed My Cat?
• Reasons Why Cats Refuse Food