Mob swabs, chicken feed, and eggs should be stackable, but they are not.

Furthermore, mob swabs (and likely chicken feed and eggs), when made stackable (using Bigger Stacks for example), behave incorrectly, consuming the entire stack rather than just one item.

minecraft 1.19.2
forge 43.3.5
mob grinding utils 1.19.2-0.4.50
bigger stacks 1.19.2-3.8.1

I'm using a modified/updated version of ATM8.

You can use this code in config/biggerstacks-rules.xml to make these items stackable for testing:

<ruleset>
	<!-- Mob Grinding Utils -->
	<rule stacksize="64">
		<or>
			<condition>id starts_with mob_grinding_utils:mob_swab</condition>
			<condition>id starts_with mob_grinding_utils:gm_chicken_feed</condition>
			<condition>id = mob_grinding_utils:nutritious_chicken_feed</condition>
			<condition>id = mob_grinding_utils:rotten_egg</condition>
			<condition>id = mob_grinding_utils:golden_egg</condition>
		</or>
	</rule>
</ruleset>

From what ive gathered talking to the original author, they were un-stackable for various technical reasons from old mc versions.

Ill add this to my list of things todo, making the unused swabs and eggs stackable, the feed wont because it contains nbt data about the monster.

the reason they dont work right with bigger stacks overriding the stack limit is they are not currently coded to work in a stack.

the feed wont because it contains nbt data about the monster.

I know with the NBT data being different it won't stack anyway, but it would allow you to put it in a bundle at least (works with Apotheosis gems and filled Utilitix mob catchers for example).