It's apparently a metaphor for something uncatchable, light of body and fleet of foot.
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捉える， 捕らえる， 捕える， とらえる
1. to catch, to capture, to seize, to arrest, to grab, to catch hold of
2. to grasp (e.g. meaning), to perceive, to capture (e.g. features)
3. to captivate, to move (one's heart)
1. to be able to do, to be possible, to be permitted (to do)
2. to be good at, to do well, to be proficient (in), to be capable
3. to come into existence, to form, to appear, to come up (of a matter), to be born, to make (a friend), to get (a girlfri...
1. thing, matter
2. incident, occurrence, event, something serious, trouble, crisis
3. circumstances, situation, state of affairs
4. work, business, affair
5. after an inflectable word, creates a noun phrase indicating something the speaker does not ...
1. thing, object, article, stuff, substance
2. one's things, possessions, property, belongings
3. things, something, anything, everything, nothing
4. quality
5. reason, the way of things
6. used to emphasize emotion, judgment, etc., used to indicate ...