MC-2025Mobs going out of fenced areas/suffocate in blocks when loading chunks
The bug
Mobs can intersect with blocks, which are right next to the mobs, when the chunk they are in was previously saved and is now loaded. This can cause the mobs to suffocate and die or to escape enclosed areas.
Reasons
This is a list of all (possibly) reasons which can cause this bug. These reasons do not exclude each other.
Bounding box precision loss
Caused by floating point inaccuracies, first described in this comment.
Explanation of bug and fix (Worth reading!)
Mobs moving in unloaded chunks
See Markku's comment but might not happen, see this comment.
Baby mobs growing up
This is definitely one reason, see this comment and MC-103313.
2012-11-03, 01:05 AM
2025-01-01, 02:36 AM
2024-12-31, 11:14 PM
1168
208
animal, area, chunk, cobblestone_wall, fence, mob, outside
Minecraft 1.4.2 - 1.21.4
Minecraft 1.4.2, Minecraft 1.4.4, Minecraft 1.4.5, Snapshot 12w50b, Minecraft 1.4.6, Minecraft 1.4.7, Snapshot 13w01b, Snapshot 13w04a, Snapshot 13w06a, Snapshot 13w07a, Snapshot 13w09c, Snapshot 13w10a, Snapshot 13w10b, Minecraft 1.5, Snapshot 13w11a, Minecraft 1.5.1, Snapshot 13w16b, Minecraft 1.5.2, Snapshot 13w17a, Snapshot 13w18c, Snapshot 13w19a, Snapshot 13w21a, Snapshot 13w21b, Snapshot 13w23b, Snapshot 13w24a, Snapshot 13w24b, Snapshot 13w25a, Snapshot 13w25b, Snapshot 13w25c, Snapshot 13w26a, Minecraft 1.6, Minecraft 1.6.1, Minecraft 1.6.2, Minecraft 1.6.4, Minecraft 13w36a, Minecraft 13w42b, Minecraft 13w43a, Minecraft 1.7, Minecraft 1.7.1, Minecraft 1.7.2, Minecraft 1.7.3, Minecraft 1.7.4, Minecraft 14w02b, Minecraft 14w02c, Minecraft 14w08a, Minecraft 1.7.5, Minecraft 14w11b, Minecraft 1.7.6-pre1, Minecraft 1.7.9, Minecraft 14w18b, Minecraft 14w21b, Minecraft 14w25b, Minecraft 14w26c, Minecraft 1.7.10, Minecraft 14w27b, Minecraft 14w28b, Minecraft 14w34b, Minecraft 14w34d, Minecraft 1.8-pre2, Minecraft 1.8, Minecraft 1.8.3, Minecraft 1.8.4, Minecraft 1.8.7, Minecraft 1.8.8, Minecraft 15w32c, Minecraft 15w34d, Minecraft 15w38b, Minecraft 1.8.9, Minecraft 16w02a, Minecraft 1.9 Pre-Release 4, Minecraft 1.9, Minecraft 1.9.1 Pre-Release 3, Minecraft 1.9.2, Minecraft 16w15b, Minecraft 1.10, Minecraft 1.10.2, Minecraft 16w32a, Minecraft 16w32b, Minecraft 16w33a, Minecraft 16w35a, Minecraft 16w36a, Minecraft 16w39a, Minecraft 16w39b, Minecraft 16w39c, Minecraft 16w40a, Minecraft 16w41a, Minecraft 16w42a, Minecraft 16w43a, Minecraft 16w44a, Minecraft 1.11 Pre-Release 1, Minecraft 1.11, Minecraft 16w50a, Minecraft 1.11.2, Minecraft 17w06a, Minecraft 1.12 Pre-Release 5, Minecraft 1.12 Pre-Release 6, Minecraft 1.12, Minecraft 1.12.1, Minecraft 1.12.2, Minecraft 1.13-pre8, Minecraft 1.14.2, 1.14.4, 20w12a, 20w17a, 20w22a, 1.16 Release Candidate 1, 1.16, 1.16.1, 20w29a, 1.16.2 Release Candidate 1, 1.16.2, 1.16.4, 20w49a, 20w51a, 21w03a, 21w05a, 21w19a, 1.17, 1.17.1, 1.18, 1.18.1, 22w03a, 1.18.2, 1.19, 1.19.1 Pre-release 2, 1.19.1 Pre-release 3, 1.19.3, 23w04a, 1.20.1, 1.21, 1.21.3, 1.21.4