When you spawn a silverfish on soul sand they take damage and eventually die.
Steps to reproduce
Place down a soul sand block.
Spawn silverfish on the soul sand.
Related issues
relates to
Comments

@unknown It says above that this affects an iOS Tablet iPad Mini...
However, I can confirm this on 0.14.3 Win 10 PC (not beta build) and also on Android 6.0.1 (Nexus 5)

It is because soul sand is actually shorter than a full block. Silverfish are small so they suffocate inside the soul sand.

actually isnt a bug, silverfish take demage on soul sand because the soul sand is 15/16 of a block and the hitbox of the silverfish stuck in the block and take demage

This is WAI.
Small mobs smaller that a slab suffocate in soul sand. Namely Silverfish and endermites (pc).
http://minecraft.gamepedia.com/Soul_sand#Usage

@unknown That is a possibility. Awaiting further input.
It's been reported and accepted as a bug on PC edition for some time, see MC-51030.
Remember the wiki often just states what happens in game, it's not an authority on whether something works as intended or not.
Addition:
This has been confirmed as a bug by a developer.

Ok @unknown. I agree with Devs overruling the wiki,
Are you running a development or beta build of win10?Sorry. Had my wires crossed. I really hope you're not running win10 insider builds on an iPad mini. 0-o