begin to be backed up / begin to be delayed

begin to be backed up / begin to be delayed

sit side by side

sit side by side / adjoin

sit side by side

be seated next to each other

spring to / fly to / hop to / jump to

hop to another [branch] / fly to another [tree] / flit from *something to *something / jump from *something to *something / fly from *something to *something / spring from *something to *something

hop to another [branch] / fly to another [tree] / fly from [one thing] to [another]

(sparks) fly