Armadillos remain scared when suffocating in a block, as opposed to armadillos in water/lava, that stop being scared as soon as they touch water/lava. This also implies that armadillo can see "through" block he is suffocating in.

How to reproduce

1. Spawn armadillo
2. Scare the armadillo
3. Put sand (or any falling block) above armadillo so the armadillo starts suffocating
4. Notice how the armadillo is still scared despite being suffocated in a block