Is this a glitch in 3rd Gen?

Question

I was grinding for Norman in the desert in Route 111, and I found a Cacnea. There was a sandstorm, and it did not affect Cacnea, even though the sandstorm affected my Breloom. Is this a glitch?

Answer 1

Cacnea has a nifty ability called Sand Veil which raises the holder's evasion in a sandstorm, and makes the holder immune to sandstorm damage. So don't worry, this is completely normal,

Comments

ok, thanks :D

Answer 2

Breloom is Grass-Fighting type.
The weather condition sandstorm only affects Rock-, Ground-, or Steel-type Pokemon.

Cacnea is Grass-type, and I see your theory.
However, this Cacnea obviously had the Sand Veil ability. The Sand Veil ability makes it immune to sandstorm, and it also increases it's evasion rate in a sandstorm.

So, there's your problem.
Hope I helped. :)

Source: Second Paragraph