Verification builds:
1.1.0.9 Retail
1.0.8.1 Retail

Summary:
You cannot sleep if there is a skeletal horse nearby. This is different the Java version.

Steps to Reproduce:

1. Try to sleep near a skeleton horse

Observed Results:
You get the message "You may not rest now, there are monsters nearby"

Expected Results:
These horses should not prevent you from sleeping, as they are not hostile mobs.

Screenshots/Videos attached: Yes

Notes:
Zombie horses also have the same effect.