Why do fish go after the largest piece of food?

[Julles]

When I feed my fish, I use a mixture of large, medium, and small pellets.  That way, everyone from the 18" koi down to the goldfish babies will have something to eat.

But it seems like the fish all try to grab the LARGEST piece of food, and then either keep pecking at something that won't fit into their mouth, or they stuff it in there and swim around with it, unable to swallow it.  I've seen them sniff and then pass up smaller pieces, just to chase a huge pellet they can't swallow.

They would have fuller tummies if they went after food that was the right size for their mouth!

[Sunbeam56]

For the same reason that we eat chocolate cheesecake. 

[miguynmkoi]

I agree with Sunbeam! 

The real shame in my pond are a few Shubs I bought a few years ago and never realized they had deformed mouths.  Their mouth openings are too small to eat the pellets other fish of the same size can easily eat.  I didn't notice until last summer while watching these few unfortunates who didn't grow as fast.  Now I have to feed the bigger fish their pellets before feeding the smaller mouth fish mini pellets or crushed foods normally saved for babies.  They are finally growing!

[Joyce]

For the same reason I go for the biggest piece of chocolate on a plate of chocolates. 

[marla]

I also use varied pellet sizes and foods and all are different colors also....mine tend to go for the small pellets though, and the larger ones are a more expensive food, so I guess that's ok