What are two examples of Natural Selection?

In a habitat there are there are red and green bugs but the birds prefer the red bugs so soon there are lot of green ones and very few red ones so then the green ones reproduce and eventually there will be no more red left

Here are examples of natural selection:In a habitat there are red bugs and green bugs. The birds prefer the taste of the red bugs, so soon there are many green bugs and few red bugs. The green bugs reproduce and make more green bugs and eventually there are no more red bugs. In an ecosystem, some giraffes have long necks and others have short ones. If something caused low-lying shrubs to die out, the giraffes with short necks would not get enough food. After a few generations, all the giraffes would have long necks.